In a major policy change, U.S. President Donald Trump's administration said on Dec. 20, it would send non-Mexican migrants who cross the U.S. southern border back to wait in Mexico while their asylum requests are processed.

The spokesman, speaking on condition of anonymity, did not specify the nationalities of those to be returned to Mexico, although the policy was aimed at helping cope with rising numbers of Central Americans seeking asylum in the United States.

The two countries have held two meetings to work out details of the plan to return migrants seeking U.S. asylum across the shared border. Mexico has said it will not accept anybody facing a credible threat in Mexican territory.

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The U.S. Department of Homeland Security did not immediately respond for comment on when the program would begin, although a department official said the policy would not apply to certain vulnerable populations and unaccompanied minors.

Serious doubts exist over whether Mexico can keep Central American asylum seekers who are fleeing poverty and crime safe, especially in border towns that are often more violent than the cities they left.

It is unclear how Mexico plans to house what could be thousands of asylum seekers for the months - or years - it takes U.S. immigration cases to be heard. A backlog of more than 800,000 cases is pending in immigration courts.

The program, dubbed Migrant Protection Protocols by the U.S. Department of Homeland Security, is one of a series of measures taken by the Trump administration aimed at making it harder for Central Americans to enter the United States under asylum laws.

Trump argues that the asylum system is abused, calling a process by which many migrants are freed in the United States to await immigration trial "catch and release."

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Trump is demanding $5.7 billion in funding for a wall along the Mexican border, triggering a U.S. partial government shutdown that stretched to its 34th day on Thursday and has left 800,000 federal workers without pay.

Illegal crossings at the southern border have dropped dramatically since highs in previous decades, but in recent years more Central American families and unaccompanied children have been migrating to the United States and applications for asylum have ballooned.

Last year, about 93,000 people sought asylum at the southern border, up 67 percent from 2017, according to U.S. government data.

REUTERS