Blinken says 'status quo was not option' in Afghanistan
"We are seeing elevated attacks on the Afghan security forces in certain parts of the country compared to a year ago," Blinken said on a visit to Paris.
He acknowledged the US had to look "very hard" to see if the Taliban was "at all" serious about bringing peace to the country.
"Actions that are trying to take the country by force are, of course, totally inconsistent with trying to find a peaceful resolution."
His comments come as Afghan leader Ashraf Ghani meets later Friday with President Joe Biden in the White House, with his government under increasing threat from an emboldened Taliban insurgency.
Biden has ordered the departure of all US forces from Afghanistan by this year's 20th anniversary of the September 11 attacks that triggered the invasion, saying he believes that no more can be achieved.