The U.S. State Department on Tuesday ordered non-essential staff to leave the U.S. Embassy in Kabul, Afghanistan due to security concerns.

The State Department said in a travel advisory that it had "ordered the departure from U.S. Embassy Kabul of U.S. government employees whose functions can be performed elsewhere."

U.S. Charge d'Affaires to Afghanistan Ross Wilson tweeted that the departure was approved "in light of increasing violence & threat reports in Kabul."

He added that the departure would affect "a relatively small number of employees at the U.S. Embassy in Kabul effective immediately."

U.S. President Joe Biden on April 14 announced plans to withdraw all U.S. combat troops from Afghanistan by September 11.

However, former U.S. President Donald Trump's administration and the Afghan Taliban had set May 1 as the deadline to pull U.S. troops out of the country. The Taliban had warned of consequences if the Biden administration fails to follow through that deadline.

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Taliban says U.S. responsible for troop withdrawal schedule from Afghanistan

There are roughly 3,500 U.S. troops in Afghanistan, and about 7,000 NATO troops in the country rely on U.S. logistics and security support.

U.S. lawmakers grilled Biden's Afghanistan peace envoy on Tuesday about how women will be protected if Taliban take control after U.S. troops withdraw, and threatened to withhold funding if rights gains are reversed.

"I don't believe under any circumstances that the United States Senate will support assistance for Afghanistan, especially under the World Bank's program which provides budget support, if the Taliban has taken a governing role that ends civil society advances and rolls back women's rights," said Senate Foreign Relations Committee Chairman Bob Menendez.

Zalmay Khalilzad, special envoy for Afghanistan reconciliation, testified at the committee's first public hearing on Afghanistan policy since Biden announced the withdrawal plans. 

Biden has said that Washington would continue providing assistance to Afghan security forces and civilian programs, including those for women and girls.

U.S. Secretary of State Antony Blinken said the Biden administration was working with Congress to provide nearly $300 million in civilian aid to the country.

(With input from agencies)

(Cover: A U.S. soldier keeps watch at an Afghan National Army base in Logar Province, Afghanistan August 5, 2018. /Reuters)