Bogotá, Colombia - Colombian President Gustavo Petro said Sunday he would block US deportation flights until migrants were guaranteed "dignified treatment," escalating a row between Washington and left-wing Latin American governments over US President Donald Trump's migration crackdown.

"The United States cannot treat Colombian migrants as criminals. I forbid entry to our territory to US planes carrying Colombian migrants," Petro wrote on X, adding they would only be accepted once Washington had established rules ensuring they would receive "dignified treatment."

In a later post, he said he had "turned back US military planes that were coming with Colombian migrants," without saying when or how many planes were involved.

He added, however, that he would allow in civilian US flights carrying deported migrants, as long as they were not treated "like criminals."

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US officials did not immediately respond to Petro's remarks, but Trump's border czar Tom Homan told ABC's This Week show on Saturday that migrants could be sent to a third country if original destination countries refused to allow flights in.

"President Trump's going to put America first," Homan said, adding that if countries refused to take back migrants, "then we'll place them in a third safe country."

Trump's threats to deport millions of migrants have put him on a potential collision course with governments in Latin America, the original home to many of the estimated 11 million undocumented migrants in the US.