U.S. President Donald Trump is likely to give troops authority to protect immigration agents stationed along the border with Mexico if they come under threat from migrants seeking to cross into the United States, an official said Monday.

Ahead of U.S. congressional elections earlier this month, Trump denounced the approach of a caravan of migrants as an "invasion" that threatened American national security, and he sent thousands of U.S. troops to the border to help secure it.

Currently, the troops do not have authority to protect U.S. Customs and Border Patrol personnel. The new authority could be announced Tuesday, the official said, speaking on condition of anonymity.