Homeland Security officials said Tuesday that among the thousands of migrants heading for the United States border are some “gang members” and people with “significant criminal histories.”

Department spokesperson Tyler Houlton said on Twitter that the caravan, 7,000 migrants strong by some estimates, includes citizens not only of Central American countries, but also of the Middle East, Africa, South Asia and “elsewhere.”

“.@DHSgov can confirm that there are individuals within the caravan who are gang members or have significant criminal histories,” another tweet read. He did not offer more specifics.

The statement by the DHS reinforced an earlier tweet from President Trump, in which he maintained that the caravan included “criminals and unknown Middle Easterners.”

Trump also said as a result of the governments’ of Guatemala, Honduras and Mexico failing to stop the migrants, the U.S. would begin “cutting off, or substantially reducing” foreign aid.

The three countries received about $500 million from the U.S. in fiscal year 2017. That money funds programs that promote economic development and education, as well as supporting democracy and human rights. It was not immediately clear how deep the cuts might go, though the administration already had been pushing to reduce the government's global aid and foreign operations budget by about 30 percent for fiscal 2019, which began Oct. 1.

The caravan has become a crucial talking point for Republicans ahead of midterm elections.

“Remember the Midterms!” Trump tweeted.

Fox News’ Andrew O’Reilly and The Associated Press contributed to this report.