PARIS: US Secretary of State Antony Blinken said on Friday Washington was assessing whether the Taliban was serious about ending the conflict in Afghanistan, and that trying to take back the country by force was not consistent with peace efforts.

Blinken, who was visiting Paris, acknowledged attacks on Afghan security forces were increasing before planned talks in Washington between President Joe Biden, Afghan President Ashraf Ghani and Ghani's former political opponent, Abdullah Abdullah.

The peace process has stalled as Afghan security forces battle a Taliban spring offensive that threatens several provincial capitals. Ethnic militias has been mobilized to help government troops.

"We are looking very carefully at the security on the ground in Afghanistan and we're also looking very hard at whether the Taliban is, at all, serious about a peaceful resolution of the conflict," Blinken told a joint news conference with France's foreign minister.

"But actions that would try take the country by force are, of course, totally inconsistent with finding a peaceful resolution."

Biden decided in April to withdraw all US troops before Sept. 11. Since then, fighting between U.S.-backed Afghan forces and the Taliban has surged.

The Pentagon estimates the Taliban now control 81 of Afghanistan's 419 district centers.

The US military has completed more than half its withdrawal from Afghanistan and is set to finish within weeks. Officials say between 600 and 700 US troops are likely to remain to help provide security for diplomats.

It is unclear how Afghan security forces will perform after US troops depart.