iStock/Thinkstock(WASHINGTON) — Donald Trump’s new executive order on immigration and travel includes a modified version of the refugee ban that existed in the original order.

Starting at 12:01 a.m. March 16, the refugee admission program will be shut down for 120 days pending review of the vetting process, although an indefinite ban on Syrian refugees has disappeared from the language.

While the ban on the refugee admission program is temporary, advocates say it will have far-reaching implications because each aspect of the application process has an expiration date.

“The imperative remains to provide protection for people fleeing deadly violence, and we are concerned that this decision, though temporary, may compound the anguish for those it affects,” said Commissioner for the United Nations High Commissioner for Refugees, Filippo Grandi. “UNHCR has long been a partner for the United States in finding solutions to refugee problems, and we look forward to continuing this partnership.”

But the U.S. Secretary of State, Rex Tillerson, said Monday: “the executive order signed by the President earlier today protecting the nation from foreign terrorist entry into the United States is a vital measure for strengthening our national security.”

Here is a look at what is expected to happen to those who are currently in the refugee application process, according to advocates.

Race Against the Clock?

According to representatives of a number of refugee resettlement agencies, the answer that there will not be a push to get refugees into the country before the deadline.

“Unfortunately, there is nothing that we or the refugees can do to speed up their travel,” Sarah Krause, senior director for programs of the immigration and refugee Program of Church World Service told ABC News.

The process applicants must go through to receive refugee status is a long and complicated one, including medical, criminal background and security checks. The Department of Homeland Security, U.S. Citizenship and Immigration Services and the State Department are all involved in the process, which can take anywhere from 6-12 months. It’s therefore nearly impossible for any applicant to expedite their case and receive approval by March 16.

Krause estimates about 400 arrivals are booked for travel per week, and she does not anticipate seeing a spike in that number this coming week, regardless of the impending new order.

Will refugees be stranded at airports again?

“This 10-day window is meant to have a more orderly processing and departure,” Hans Van de Weerd, vice president for U.S. programs at the International Rescue Committee, told ABC News. “We are not expecting the same transit issues. However, one can never be entirely sure.”

What will happen to those who are waiting in line to get to the United States?

There are about 10,000 refugees who have been approved to relocate to the United States, van de Weerd said, and their cases have “Must Travel By” dates. If an individual is not able to travel to the United States before that date, they may be required to go through the clearance process again.

Each step requires waiting for availability, and while waiting for one item, others may continue to expire. Any life event that occurs during the 120-day suspension period, such as a birth, death, marriage or even birthday (for children turning 14) will quire new or repeated checks.

“It’s likely to set off a series of expiries meaning that refugees who could have traveled in a few weeks may be delayed by months, and in the worst case scenario, years,” Krause said.

Will there be any exceptions for refugees who have already been approved?

The new executive order states that the 120-day travel suspension “shall not apply to refugee applicants who, before the effective date of this order, have been formally scheduled for transit by the Department of State.”

However, the refugee resettlement agencies ABC News spoke with did not have any details from government officials on how this exception would work in practice.

And van de Weerd added that because of the expiration dates on applications, “many will lose and go to the back of the queue. This is not an innocent pause, but a setback to the refugee program as a whole.”

The executive order also mentions that the secretaries of State and Homeland Security may jointly admit refugees on a case-by-case basis, including in situations in which the denial of entry would cause “undue hardship.”

Legal experts told ABC News that what constitutes “undue hardship” is unclear and can be widely defined, but that precedent has shown that separation from a spouse or family members, for example, may not rise to the level of undue hardship.

Van de Weerd said he could see denying refugees who require immediate and emergency medical attention as “undue hardship.”

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