The Trump administration will temporarily delay the processing of most refugees from 11 countries deemed to be high-risk while resuming refugee admissions for other countries, government officials said on Tuesday.

According to a memo, sent by the Trump administration to Congress on Tuesday ahead of the government announcement on new refugee vetting measures, the administration also will place on hold a program that allows for family reunification for some refugees resettled in the United States.

The resettling of so-called following-to-join refugees will resume, according to the memo, once screening "enhancements have been implemented."

The changes come at the close of a 120-day ban on most refugees that was ordered by President Donald Trump to allow a review of vetting processes. The 120 days ended on Tuesday, and Trump issued an executive order providing for the general resumption of the US refugee program.

"We continue to have concerns regarding the admission of nationals of ... 11 particular countries" deemed to be high-risk, the memo said. It said the government will conduct a 90-day review "to determine what additional safeguards, if any, are necessary to ensure that the admission of refugees from these countries of concern does not pose a threat to the security and welfare of the United States."

Trump took office in January with a goal of sharply cutting refugee admissions, in line with the hard-line immigration policies that were a focal point of the Republican’s 2016 election campaign. He quickly issued the temporary bans on refugees and travelers from several Muslim-majority countries, which were challenged in court.

Opponents of the bans argued that the policies were aimed at barring Muslims from the United States. The administration has denied any intent to discriminate and argued that its travel ban and security changes were meant to protect the United States from terrorist acts.

The memo said that refugees from countries that do not require higher-level security screening, known as Security Advisory Opinions, or SAOs, will temporarily be prioritized over the 11 countries, since their "processing may not be as resource intensive."

As of the end of 2016, SAOs were required for most adult male nationals of Egypt, Iran, Iraq, Libya, Mali, the DPRK, Somalia, South Sudan, Sudan, Syria and Yemen, as well as Palestinians who lived in those countries. Others who are considered "stateless" by the United States who lived in one of the 11 countries also fall under the mandatory SAO requirement, according to a State Department document seen by Reuters. Three sources familiar with refugee processing said that list was still current.

Refugee advocates said the administration's decision would essentially pause admissions for applicants from those nations.