DOHA, Qatar -- Secretary of State John Kerry warned Saturday that the newly opened Taliban office here "has to be closed" if the insurgents do not respond to demands that they negotiate in good faith.
The prospects of three-way Afghan peace talks have been thrown into doubt by the Taliban's efforts to give their office here the trappings of an embassy, which the American and Afghan governments see as overreaching and in violation of the terms of the negotiations.
Mr. Kerry's remarks came at a news conference with the Qatari prime minister, Hamad bin Jassim bin Jaber al-Thani, after a meeting of the 11-nation Friends of Syria group. The group agreed to step up its aid to Syrian rebels in response to intervention by Iran and the Lebanese militia Hezbollah in the conflict.
American and Afghan officials insist that the Taliban violated an agreement to open a political office in Qatar by presenting it as a quasi-embassy, flying their flag and posting signs reading "Islamic Emirate of Afghanistan" when it opened Tuesday.
On Friday, a senior Taliban official, speaking by telephone from Islamabad, Pakistan, said the insurgents had no intention of removing their flag or sign. "The government of America and of Qatar backtracked on the promise they made to us on the flag and the name," the official said. "It was agreed we could use them." He spoke on the condition of anonymity because the Taliban have officially canceled all interviews until they decide on a public response to the issue.
In anger over the Taliban move, Afghan officials broke off talks on future military cooperation with the United States, and said they would not be sending representatives to Qatar for the talks. American officials insisted that the Taliban office was purely for the purpose of getting talks started with the group.
"Regrettably the agreement was not adhered to," Mr. Kerry said Saturday. He said intervention by the Qatari government had persuaded the Taliban to "step back" from their stance -- they lowered the flag so it could not be seen from outside their office's compound, for instance. "Now we need to see if we can move forward. If not we may have to consider whether or not the office will have to be closed."
Mr. Kerry said the chief American negotiator, James Dobbins, was in Doha and "waiting to find out whether the Taliban will respond."
The first step in talks with the Taliban would involve discussions with American officials over a prisoner swap, in which senior Taliban prisoners held at Guantánamo Bay, Cuba, would be exchanged for the lone American P.O.W. held by the Taliban, Bowe Bergdahl.
On Syria, Mr. Kerry met with foreign ministers from European and Arab nations on Saturday to discuss what concrete steps could be taken to strengthen the Syrian opposition militarily. It was first time the coalition had met since President Obama decided that the United States would send ammunition and weapons covertly to the opposition.
Mr. Kerry said the group would increase its military support to the rebels but declined to say what types of weapons would be provided. He said that each member had discussed what additional steps it might take and that the Obama administration would build on those plans "in order to have an impact on the ground."
"It is not anything we say today that will make the difference to Assad," he said of the Syrian president, Bashar al-Assad. "It's what happens in the days, and weeks and months ahead, and, I hope, not too many months."
A communiqué issued by the group was also vague, referring only to its agreement to take "urgent practical steps to support the Syrian opposition." Besides the United States and Qatar, the group includes Britain, Egypt, France, Germany, Italy, Jordan, Saudi Arabia, Turkey and the United Arab Emirates.
Criticizing the "internationalization" of the war, Mr. Kerry said the additional assistance was needed not just because American intelligence had concluded that Mr. Assad's forces had used chemical weapons but also because of intervention by Hezbollah and Iran on the side of the Assad government.
"What is different is that this is now a response to what Iran and Hezbollah are doing," he said.
Mr. Kerry denounced Hezbollah as a "terrorist" organization and said that Iran's intervention risked a wider Shiite-Sunni war.
He also said that Russia had continued to supply arms to the Assad government while "ostensibly" talking about the need for a political solution.
Mr. Kerry added, however, that Russia's president, Vladimir V. Putin, still supported the proposal to hold an international peace conference on Syria and that a planning meeting with Russian, American and United Nations officials for that conference would take place this week in Geneva.
This article originally appeared in The New York Times.