"I am here to work closely with our allies, with the (NATO) secretary-general, on the principle that we have established from the start: In together, adapt together and out together," US Secretary of State Antony Blinken said in a televised statement at NATO headquarters in Brussels, Reuters reported.
"We will work very closely together in the months ahead on a safe, deliberate and coordinated withdrawal of our forces from Afghanistan," Blinken said, standing alongside NATO Secretary-General Jens Stoltenberg.
NATO foreign and defense ministers will discuss their plans later via a videoconference. A senior NATO diplomat told Reuters that no ally was expected to oppose US President Joe Biden's formal announcement for a complete US withdrawal of troops by Sept. 11.
The US has some 2,500 troops in Afghanistan as part of a 9,600-strong NATO mission in the country.
The US, along with its NATO allies, invaded Afghanistan in October 2001. The invasion — which has led to the longest war in US history — removed the Taliban from power, but the militant group never stopped its attacks.
Washington has spent trillions of dollars waging the war on Afghanistan, which has left tens of thousands of Afghan civilians and thousands of American soldiers dead, Press TV wrote.
A US official said on Tuesday that Biden had reached the conclusion to end Washington's two-decade involvement in Afghanistan.
German Defense Minister Annegret Kramp-Karrenbauer said Wednesday that NATO will likely join the United States in withdrawing all troops from Afghanistan.
"We always said: We'll go in together, we'll leave together," she told ARD public television. "I am for an orderly withdrawal."
With around 1,000 troops, Germany has the second-largest contingent deployed to Afghanistan after the United States.
NATO allies including Germany had been waiting for Biden to decide whether the US would stick to a May 1 deadline to withdraw under a deal struck between the administration of former US leader Donald Trump and the Taliban.
Britain is also preparing to follow the US in pulling its troops out of Afghanistan by September, according to a report Wednesday that was not denied by the government.
"We are working closely with the US, NATO allies and partners to support a secure and stable Afghanistan," a government spokesman told AFP in response to the report by The Times newspaper.
Taliban to boycott Turkey summit
The Taliban said on Tuesday that it will not attend a summit on Afghanistan's future, due to be held in Turkey from April 24 to May 4, until all foreign forces leave the country.
"Until all foreign forces completely withdraw from our homeland, (we) will not participate in any conference that shall make decisions about Afghanistan," tweeted Mohammad Naeem, spokesman for the Taliban office in Qatar.
A diplomatic source told Reuters that more than 20 countries had been invited, including Iran and Afghanistan’s other neighbors.
UN spokesman Stephane Dujarric has told reporters in New York that “we very much hope” the Taliban will attend.
Under a February 2020 deal between the Taliban and the Trump administration, Washington vowed to withdraw all the US troops remaining in Afghanistan. In return, the Taliban pledged to stop attacks on US troops.