Ukrainian citizens walk along with advocates on the Mexican side of the border on March 9, 2022.
CNN  — 

A Ukrainian woman and her three children crossed into the United States on Thursday after being turned away at the US-Mexico border a day earlier, according to the family’s attorney.

On Thursday, Vice President Kamala Harris committed to taking in more Ukrainian refugees on an overseas trip, but just hours earlier, the Ukrainian family had been barred from claiming asylum in the US, according to their attorney and advocates on the ground.

For nearly two years, the US southern border has largely been closed off to asylum seekers because of a public health order invoked under the Trump administration at the onset of the coronavirus pandemic.

Since its implementation in March 2020, the use of the public health authority – Title 42 – has fielded fierce criticism from President Joe Biden’s allies and this week, it stood in stark contrast to the position European countries have taken to Ukrainian refugees.

More than 2 million people have fled war-torn Ukraine within the last few weeks, with most going to Poland. During a visit in Warsaw Thursday, Harris pledged support to addressing the massive flow of migrants coming from Ukraine and said the US was willing to take in more migrants.

“The US is absolutely prepared to do what we can and what we must,” Harris said.

But back at home, the strict border policies that have left thousands of migrants in limbo also kept out a Ukrainian family fleeing the war.

The Ukrainian woman and her children – aged six, 12 and 14 – tried to claim asylum at the San Ysidro port of entry in southern California, but US Customs and Border Protection officials denied them entry, citing the Trump-era border policy that remains in effect, according to Blaine Bookey, who spoke with the officials and is representing the family.

The family arrived in Tijuana, Mexico, which sits across from San Diego, on Monday after fleeing Ukraine in late February, Bookey said.

The family had approached CBP officers Wednesday, but they wouldn’t let the mother and children pass onto US soil, therefore keeping them from claiming asylum in the US. “They had to leave because they’re fleeing the war,” Bookey, legal director at the Center for Gender and Refugee Studies, said. “She doesn’t know what’s going on,” Bookey added, referring to the mother.

Senate Majority Leader Chuck Schumer, a New York Democrat, cited the situation during a call with reporters as part of his plea to the administration to end Title 42.

“This is not, this is not who we are as a country,” Schumer said.

Why migrants have come through Mexico

Ukrainians have been trying to cross the US-Mexico border since before the war this year and make up only a small portion of the nationalities who arrive at the border. From October 2021 through January, CBP encountered just over 1,000 Ukrainians along the US southern border, according to agency data. Once taken into custody, the Ukrainians have largely been processed and allowed to remain in the US while they pursue their asylum claims.

“Since at least 2015, we’ve seen several hundred Ukrainians arriving at the US-Mexico border. That number started to increase in 2021 and has increased even more rapidly so far in fiscal year 2022,” said Jessica Bolter, associate policy analyst at the Migration Policy Institute.

Ukrainians have generally flown to Mexico, where it’s easy to obtain a visa to travel, and then gone to ports of entry along the US southern border instead of trying to cross unlawfully, Bolter added.

The San Ysidro port of entry has seen a steady increase in Ukrainian and Russian migrants over several months, with some opting to drive to the port to claim asylum to avoid being turned away before reaching US soil, according to a CBP official.

The US is providing millions of dollars in humanitarian assistance to support people fleeing Ukraine. Harris on Thursday also announced nearly $53 million in new humanitarian assistance from through the US Agency for International Development.

Most Ukrainian refugees are headed to other parts of Europe, but refugee advocates have also urged the administration to expedite the refugee resettlement process, which can be long and cumbersome, for Ukrainians. The US previously resettled thousands of Ukrainian refugees, but it’s unclear how many will ultimately come to the United States as refugees as a result of the current conflict.

The Department of Homeland Security recently extended a form of humanitarian relief to Ukrainians in the US that allows them to remain in the country and provides protection from deportation when their visas expire. The relief – known as Temporary Protected Status – only applies to people who are already in the US.