The TV blitz was an effort to reassure critics after President Joe Biden came under fire for his decision on Friday to keep this year's refugee limit at 15,000, the same level set by former president Donald Trump.

The White House, faced with angry Democrats accusing Biden of perpetuating Trump's anti-immigrant policy, quickly changed course and said it would raise the limit in May.

"[Biden] is absolutely committed to making sure that America is not only welcoming to refugees but also that we raise the cap," National Security Advisor Jake Sullivan told "Fox News Sunday." "He is committed to that, and we are following through on that."

On his first day in office, Biden ended Trump's travel ban on people from predominantly Muslim countries.

Sullivan characterised that move as a "first step" in Biden's immigration policy and that a "second step" of raising the limit on refugees would take place in the coming weeks.

Secretary of State Anthony Blinken indicated that the number would be higher than 15,000, but lower than the 62,500 that Biden had previously promised by October 1, the end of the fiscal year.

"It's going to be very hard to meet the 62,000 this fiscal year," Blinken told ABC's "This Week."

"We're able to start to bring people in who've been in the pipeline and who weren't able to come in. That is starting today, and we're going to revisit it in the middle of May," he said.

The emergency declaration Biden signed on Friday includes more refugee slots for people from Central America, Africa and the Middle East.

The policy changes come as migration through Mexico to the US has been increasing.

A record number of children traveling alone crossed the border in March. The surge came as Biden exempted unaccompanied minors from emergency expulsion powers that Trump declared during the pandemic.

Australian Associated Press