The agency did not respond to requests for comment on Tuesday about the intelligence assessment.

Officials said the Trump administration has not decided whether to shift the mission of the 5,900 active-duty troops who were deployed to the border ahead of an approaching migrant caravan from Central America. Talks are ongoing, said one Defense Department official who was not authorized to speak about the deliberations.

Military documents have predicted that only a small percentage of the migrants will make it to the border. Col. Rob Manning, a Pentagon spokesman, said in a statement Tuesday that the cost of deploying the military troops was expected to reach $72 million so far.

Currently, the troops are authorized to use military force only for self-defense. The White House is pushing to give the soldiers and Marines explicit authority, in writing, to accompany and defend agents who might come under attack, administration officials said.

Defense Secretary Jim Mattis is expected to accede to the White House wishes, according to the officials, all of whom spoke on condition of anonymity to discuss the internal talks.

More than 3,200 migrants from the caravan have reached the border city of Tijuana, Mexico, where they may have to wait for months if they decide to seek legal entry. Officials estimate that the number could reach more than 10,000. An additional 3,000 migrants are in the border city of Mexicali, about 100 miles east of Tijuana, according to reports from Customs and Border Protection.