Panamanian police on Tuesday turned back dozens of migrants, mostly Venezuelans, trying to return home after abandoning their journey to the United States due to President Donald Trump's deportation policies.

Riot police forced the caravan to go back to Costa Rica to undergo an orderly repatriation process.

"We went in search of a dream that could not be fulfilled and now we are heading back home again," a migrant who did not give his name told AFP.

Venezuelan Andres Paredes said he wanted to avoid going hungry and sleeping on the streets during the long journey to the United States, only to be turned away.

At a shelter in Costa Rica, the migrants will undergo biometric checks for criminal records and then be bussed to Panama for repatriation by air or sea, Panama's security ministry said in a statement.

"We want to ensure an orderly, legal, humanitarian and safe flow of migration," the statement quoted Costa Rican Security Minister Mario Zamora as saying.

Many of the migrants had previously made the dangerous trek from Colombia to Panama through the lawless Darien jungle.

On his first day back in office last month, Trump declared a national emergency at the southern US border and vowed to deport "millions and millions" of migrants.

Following an agreement signed with Washington in July, Panama has closed several routes in the Darien region and deported migrants on flights to countries including Colombia and Ecuador with US financial support.