He made the pledge ahead of meetings with European defence and foreign ministers during his first official trip to the continent.
President Joe Biden said last week that it would be tough for Washington to meet the looming 1st May deadline deadline that his predecessor Donald Trump agreed with the Taliban.
Nato allies have said they are willing to stay in Afghanistan longer if the US remains too, but they are keen for Washington to make up its mind.
Blinken said the US was still mulling over the future of the alliance's 9,600-strong mission.
"We have a review under way in the United States," said Blinken. "I'm here in part to share some of our initial thinking with our Nato allies.
"But maybe even more important, I'm here to listen and consult because that is what allies do."
The Taliban, has warned that the US would be responsible for the consequences if it reneged on the arrangement.
Vital American support
Trump slashed US troop numbers to 2,500, the lowest level in two decades, but American support remains vital to keep the Nato mission going.
In the deal, the Taliban agreed to cut violence. However the US has complained that talks have stalled and bloodshed has flared.
The US and its allies are desperate to keep Afghanistan from becoming a haven for terror groups. "Whatever the United States ends up doing will be informed by the thinking of our NATO allies, which I'll take back with me after these conversations," Blinken said.
"We are united with our Nato allies in seeking to bring a responsible end to this conflict, and to remove our troops from harm's way."
The visit by Blinken, which also includes meetings with top EU officials, aims to make good on Biden's assurances that the US wants to work closely with its allies.
"I've come to Brussels because the United States wants to rebuild our partnerships, first and foremost, with our Nato allies," Blinken said.
"We want to revitalise the alliance, to make sure it's as strong and effective against the threats of today, as it has been in the past."
