President Donald Trump claimed "Many Gang Members" and "some very bad people" are mixed into the caravan of migrants slowly moving north through Mexico toward the U.S., calling it an "invasion of Our Country" and that the U.S. military is "waiting for you."

"Please go back, you will not be admitted into the United States unless you go through the legal process," Trump said on Twitter Monday.

?The caravan of migrants from Honduras and Guatemala, making its way north on foot, is still hundreds of kilometers away from the closest U.S. border.

Members of a US-bound migrant caravan stand on a r
Members of a US-bound migrant caravan stand on a road after federal police briefly blocked their way outside the town of Arriaga, Oct. 27, 2018.

The Pentagon has approved a request by the Department of Homeland Security to send hundreds of troops to the U.S.-Mexico border in what is described as a support role. A statement said personnel will support the border patrol with planning assistance, medical teams and the construction of temporary housing, along with other support duties. News reports Monday suggested the deployment could involve thousands of troops.

Defense Secretary Jim Mattis has said details are being worked out.

The troops will join more than 2,000 members of the National Guard already deployed to the area who are providing support for border patrol agents.

Meanwhile, the Trump administration is reported to be considering a new executive order aimed at blocking asylum seekers and immigrants from crossing the U.S.-Mexico border.
News reports quoting unnamed administration officials say authorities are weighing a range of administrative and legal actions on grounds of national security to restrict the ability of migrants to seek asylum.
Although no decision has reportedly been made yet, immigration attorneys told VOA the move would be quickly challenged in court.
The U.N. refugee agency is urging Washington to allow people fleeing persecution and violence, including those who are traveling with the Central American caravan, to request asylum on U.S. territory.  

“Our position globally is that the individuals who are fleeing persecution and violence need to be given access to territory and protection including refugee status and determination procedure," UNHCR spokesman Andrej Mahecic told VOA.  "And, if the people who are fleeing persecution and violence enter Mexico, they need to be provided access to the Mexican asylum system and those entering the United States need to be provided access to the American asylum system.”   

Most of those traveling north are from Honduras. There has been no evidence to back up President Donald Trump's claim last week that "Middle Easterners" are also with the group.

Lisa Schlein, Aline Barros contributed to this report.