Joe Biden authorized thousands more U.S. troops to deploy to Afghanistan on Saturday as the Taliban continued to capture provincial capitals and was said to be closing in on Kabul.

Biden said he’s authorized “approximately 5,000 US troops” to deploy based on “recommendations of our diplomatic, military, and intelligence teams.” The troops will deploy to protect the evacuation of U.S. personnel and Afghan allies, Biden said.

Biden also said he warned the Taliban that “any action on their part on the ground in Afghanistan, that puts US personnel or our mission at risk there, will be met with a swift and strong US military response.”

Biden’s authorization of 5,000 total troops in Afghanistan is an increase of about 1,000 troops from the approximately 1,000 troops that were already deployed in the country at the start of the week and a deployment of 3,000 troops the Pentagon announced on Thursday.

On Thursday, Pentagon spokesman John Kirby had confirmed two U.S. Marine Corps infantry battalions and one U.S. Army infantry battalion— a force of about 3,000 U.S. troops — would deploy within the ensuring two days to provide security for U.S. personnel evacuating from the U.S. Embassy in Kabul.

The additional 1,000 troops consist of the lead battalion of the 82nd Airborne Brigade Combat Team (BCT), which deployed to Kuwait earlier this week to be on standby if the situation in Afghanistan called for additional U.S. troops

The rapid addition of 5,000 U.S. troops in Afghanistan comes about two weeks before the U.S. was set to conclude combat operations in the country, on August 31st, and about a month before U.S. forces were set to withdraw entirely from the country, on September 11.

On Saturday, the Taliban captured its 21st of Afghanistan’s 34 provincial capitals.

In addition to rapidly capturing the Afghan provincial capitals, the Taliban has also gotten its hands on dozens of military vehicles, including humvees, Mine Resistant Ambush Protected (MRAP) vehicles and ScanEagle drones the U.S. either donated or left behind for the Afghan government.

“One more year, or five more years, of US military presence would not have made a difference if the Afghan military cannot or will not hold its own country,” Biden said in his statement.