MEXICO CITY Mexico's national migration institute (INM) on Friday said it has asked the foreign ministry to make diplomatic arrangements with Brazil, Colombia, Cuba, Nicaragua and Venezuela for the countries to accept migrant return flights.

More migrants have been passing through Mexico to the U.S. border, including large numbers on dangerous cargo trains, and the institute said it has registered more than 1.5 million foreigners entering the country irregularly this year.

It also said migration officials have established 30 checkpoints along cargo railways as part of an agreement with railroad operator Ferromex, which last month suspended some north-bound train routes due to migrants hitching rides.

In the last three weeks, more than 27,000 migrants have been "persuaded to get down from trains," INM said in a statement.

The U.S. has also been grappling with thousands of migrants entering the country, and this week said it was restarting deportations of Venezuelans.

Mexico's foreign ministry did not immediately respond to a request for comment. INM said it sought help from the ministry so that Brazil, Colombia, Cuba, Nicaragua and Venezuela would accept "assisted returns via air."

INM also said it had hired charter planes and buses to transport migrants within Mexico, as well as to their home countries.

(Reporting by Diego Ore; Writing by Brendan O'Boyle and Daina Beth Solomon; Editing by Isabel Woodford)