Troubling drone footage emerged online Sunday that reportedly showed up to 1,000 migrants being held by border patrol in Mission, Texas, prompted criticism from Republicans who said the footage underscores the crisis at the border.

"An absolute catastrophe from Joe Biden, Kamala Harris, and House & Senate Democrats," Rep. Elise Stefanik, R-N.Y., posted on Twitter. 

She retweeted a post from Bill Melugin, a Fox News national correspondent. He said the footage showed the "largest group of migrants we’ve ever seen being held by Border Patrol under Anzalduas Bridge in Mission, TX."

"Looks like it could be up to 1,000 people," he posted. "We can only get a look at the area with our drone. There’s a popular Rio Grande crossing area nearby."

Border Patrol did not immediately respond to an after-hours email from Fox News seeking comment about the video.

Republicans have been critical of the Biden administration over its handling of the border issue. They say the president should be more assertive in getting the problem under control given that there is a global pandemic.

Gov. Greg Abbott, a Republican, announced last week that he would deploy the Texas National Guard to help troopers make arrests at the border.

"To respond to this disaster and secure the rule of law at our Southern border, more manpower is needed," Abbott wrote in a letter to Maj. Gen. Tracy R. Norris, adjutant general of the Texas National Guard.

GET THE FOX NEWS APP

U.S. officials reported this month that they had encountered 55,805 members of families with children in June, up 25% from the previous month. That figure still remains far below the high of 88,587 in May 2019.

The Associated Press contributed to this report