WASHINGTON (Reuters) - The United States will focus on securing the Kabul airport and additional U.S. forces will flow into the airport on Monday and Tuesday, U.S. Deputy National Security Adviser Jon Finer said, as people tried to flee a day after Taliban insurgents seized the Afghan capital.

The United States has temporarily halted all evacuation flights from Kabul to clear people who had converged on the airfield, a U.S. defense official told Reuters, but did not say how long the pause would last.

The defense official said the United States intent was to get tens of thousands of at-risk Afghans who worked for the U.S. government out of Afghanistan and was looking at temporarily housing them at Fort McCoy in Wisconsin and Fort Bliss in Texas.

Five people were killed in chaos at Kabul airport on Monday, witnesses said, as people tried to flee after Taliban insurgents seized Kabul and declared the war against foreign and local forces over.

U.S. Deputy National Security Adviser Jon Finer said that the U.S. was focused intensively on securing the Kabul airport on Monday in order to continue civilian evacuation flights for American citizens in Afghanistan, Afghans who worked alongside the U.S. over the past 20 years and for other particularly vulnerable Afghans.

"The main focus of our efforts today are going to be getting that airport back up and running so the flights can continue," Finer told MSNBC.

Additional U.S. forces will be flowing into the airport on Monday and Tuesday to provide security, he added.

Taliban insurgents took control of the Afghan capital Kabul on Sunday following a rout of the U.S.-backed Afghan army as foreign forces withdrew from Afghanistan.

(Reporting by Idrees Ali, Daphne Psaledakis, Lisa Lambert and Humeyra Pamuk; Editing by Giles Elgood and Nick Zieminski)