Foreign students who have been admitted to U.S. colleges this fall are struggling to secure visas, threatening to deprive U.S. colleges of billions of dollars for the second year in a row.

Refugees who expected to be admitted to the country after Biden proposed increasing the admissions cap have been turned away after the administration failed to make it official.

And Biden’s administration has not withdrawn from court cases former president Donald Trump was pursuing to keep immigrants out of the country.

Biden is staring down a lengthy immigration to-do list, including items related to the pandemic, which is compounding one of the country’s most contentious and complicated issues, according to interviews with more than half a dozen current and former administration officials and immigration advocates who work with the White House.

Millions of immigrants — from those fleeing chaos at home to wealthy foreign investors — face problems either getting into the country or confusing and contradictory policies once they get here. Most of the attention has been on the crisis at the southern border, where migrant numbers have surged and unaccompanied children are being housed in shelters. But a myriad of other problems abound.

“The fact that European billionaire CEOs who have been vaccinated can’t enter the U.S. but people can cross the southern border shows the lack of coherency of the policies of the administration,” said a former Obama official who is in touch with the Department of Homeland Security.

Biden will be forced to make some highly consequential decisions in the coming weeks — whether to reopen the United States’ borders with Mexico and Canada by March 21 and whether to lift a ban on most foreign workers by March 31 — but he’ll likely make them without his top staff in place.

He hasn’t named nominees to lead the Immigration and Customs Enforcement, Customs and Border Protection and Citizenship and Immigration Services, leaving some staffers and immigration advocates concerned about the delay, according to two people familiar with DHS deliberations on immigration.

And the Senate has once again delayed confirming Biden’s nominee for attorney general, Merrick Garland, last week, postponing the hiring of the high-ranking Justice Department official who will focus on dismantling Trump’s immigration policies.

“Part of it, the frustration is that a lot of folks in immigrant communities, the average person doesn’t understand the intricacies of how the federal government works, staffing, confirmations,” said Marielena Hincapié, the executive director of the National Immigration Law Center. “They just want change.”

It was always going to be difficult for Biden to fulfill his pledge of reversing Trump’s restrictive immigration policies because of the lengthy regulatory process, legal challenges to his executive orders and a recalcitrant Congress that already dodged this issue. But in some areas, Biden’s team has yet to act.

The Department of Homeland Security is compiling a list of policies they can challenge in the courts. (Overturning those policies without the courts is a complicated process.) These are policies created under Chad Wolf, Trump’s last acting Homeland Security secretary after a federal judge andCongress concluded he was not lawfully serving in the role since he lacked Senate confirmation. If they succeed, 50 policies could be impacted — everything from dramatic fee increases, including a first-ever fee for asylum applicants, to more questions on the citizenship test. But those challenges have yet to be made, according to Hincapié and the former Obama official.

The new secretary of Homeland Security, Alejandro Mayorkas, has asked for patience, saying he learned after his swearing-in on Feb. 2 that the Trump administration had “dismantled” the nation’s immigration system.

“We did not have the facilities available [nor are we] equipped to administer the humanitarian laws that our Congress passed years ago,” he said at a briefing at the White House last week. “We did not have the personnel, policies, procedures or training to administer those laws. Quite frankly, the entire system was gutted.”

Trump reshaped virtually every part of the U.S. immigration system through executive action, policy guidance and regulatory change.

In total, he made more than 400 changes to immigration policy in the last four years, according to the Migration Policy Institute, a think tank. The Immigration Policy Tracking Project, run by former Obama Homeland Security official, Lucas Guttentag, puts that number closer to 1,000.

Biden has made fighting the coronavirus, which is still infecting tens of thousands and killing 2,000 Americans each day, his top priority. After he helps bring the pandemic under control, he plans to tackle several issues, including the economy, infrastructure, gun restrictions and immigration.

In addition to Trump’s changes, the circumstances surrounding immigration on the ground have changed, making it impossible for Biden to try to just return to pre-2016 policies.

“[Dismantling and distorting the immigration system] was the single minded mission of the Trump administration agenda,” said Guttentag, an immigration professor at Stanford Law School.

And Trump succeeded, he said. But Biden’s unprecedented barrage of early actions clearly demonstrates his commitment to addressing the shambles he inherited, he said.

“But I think the administration also rightly recognizes that immigration is not the only issue facing the country,” Guttentag said, “and right now we have both a genuine pandemic and an economic crisis that demand attention.”

On his first day in office, Biden released a massive immigration package and signed several immigration-related executive orders to halt construction of the border wall, end a ban from some majority-Muslim nations and restart a program to protect so-called Dreamers.

Cass Sunstein, a top Obama official who worked with Biden decades ago on Capitol Hill, was hired as a senior counselor at DHS to put in place Biden rules and regulations that could withstand legal challenges.

But Biden has yet to address a series of issues: He punted on whether high-skilled workers should be given preference if they are being hired at companies paying more money instead of through a random lottery. He hasn’t fulfilled a campaign promise to tackle the massive backlog at immigration courts that doubled under Trump. (Even with the backlog, many of those cases were denied.)

And last month, he called for a review of the so-called public charge rule that makes it harder for immigrants who rely on public benefits, such as Medicaid, to obtain permanent residency in the country.

“I think it’s very, very harmful to immigrants who become fearful that using any kind of program would jeopardize their green card even if they have every legal right to access them,” said Rep. Judy Chu (D-Calif.), who will help push immigration legislation through the House.

“I’m very anxious about it, so I would have liked to have a straight rule to rescind it.”

Biden will be forced to make decisions on some issues, including the closure of the southern border and granting visas to more than 100,000 foreign workers. But it’s not clear when — or if — he will act at all on others, including fighting court cases and changing the refugee caps.

An administration official said no timeline or update is available for changes to the refugee cap but that the administration is in close touch with Congress on the issue. “While no firm numbers have been finalized, the president’s view is clear: This program will reflect the generosity and core values of the United States while benefitting from the many contributions that refugees make to our country,” the official said.

One of the most pressing issues Biden faces: to allow temporary migrants, such as students, easier access to visas, even though many consulates and embassies are closed. Only 43 of 233 processing centers for guests are processing routine cases, according to the State Department.

Groups representing U.S. colleges had a virtual meeting last week with Esther Olavarria, deputy director of the Domestic Policy Council for Immigration, and Tyler Moran, special assistant to the president for immigration for the Domestic Policy Council, according to the former Obama official and a higher education official familiar with the meeting who is not authorized to speak for the colleges.

“International students we have admitted for the fall of 2021 will be in the process of evaluating offers of admission over the next two months,” said Katherine Newman, chancellor for academic programs for the University of Massachusetts system. “If they are not certain that they will be able to secure visas to the U.S., they are likely to look toward other countries that make the process easier and more reliable.”

International students used to make up nearly 1 in 10 students in the University of Massachusetts system. The loss of foreign students cost the system more than $17 million dollars in revenue in the 2019-2020 academic year.

Before Trump came into office, nearly 500,000 new foreign students came into the United States in a year, pumping billions of dollars into small and large schools across the country. That number slowly declined under the former president and plummeted last year.

Julie Stufft, acting deputy assistant secretary for visa services, acknowledged the problems in securing visas last week. She said her office is working to solve the problem, though those who plan to reside in the U.S. permanently take precedent. Some immigrants from select countries, including China and much of Europe, are still banned from traveling to the U.S. due to the pandemic.

Gregory Chen, senior director of government relations at the American Immigration Lawyers Association, said the Biden administration deserves credit for pursuing many of the reforms he had pledged to do during the campaign. But, Chen said, “The jury is still out on whether they are going to be successful in implementing those policies.”