Thousands of troops will be headed to the U.S.-Mexico border to meet President Donald Trump’s request to enhance security there, the Pentagon confirmed Tuesday.

While no decision has been made on the exact number or make up of the troops, they will be tasked with adding more concertina wire to the U.S.-Mexico border and supporting surveillance, DoD said in a clarifying statement following Acting Defense Secretary Patrick Shanahan’s press briefing Tuesday.

In that briefing, Shanahan said that DoD had informed DHS that the additional capabilities DHS was requesting would take “several thousand” additional forces to complete. But he did not confirm that that level of additional forces would be provided.

Democrats want to know why active-duty troops are still on the southern US border More than 2,000 active-duty troops are still deployed there, months after President Trump said there was an imminent immigration threat.

Later Tuesday, DoD sent a statement confirming there would be another large deployment.

“As the Acting Secretary said, we are supporting our federal partners on the border and that mission has been extended until September. We are currently sourcing the units involved and there will be an increase of a few thousand troops. We will provide more clarity on the numbers when we have it," DoD said.

The news comes just as the Chairman of the House Armed Services Committee. Adam Smith, D-Wash., questioned why active duty forces were still on the border at all.

“Border security is important, but we have other needs in the world,” said Smith, during a Congressional hearing on the border deployment Tuesday. “We also have ISIS and Syria and Russia and China … (The southern border) is not primary to the military’s mission.”

× Fear of missing out? Sign up for the Early Bird Brief - a daily roundup of military and defense news stories from around the globe. Thanks for signing up. By giving us your email, you are opting in to the Early Bird Brief.

The current extension of active duty forces to the border runs through September.