The Taliban has temporarily closed its office in Qatar, where it was hoped peace talks would begin with the US and Afghanistan, an insurgent official said on Tuesday, blaming "broken promises".
The office opened on June 18 as the first move towards a possible peace deal after 12-years of fighting, but it enraged Afghan President Hamid Karzai by styling itself as an unofficial embassy for a government-in-exile.
"We have temporarily closed the Qatar office due to broken promises," a Pakistan-based Taliban official, said on Tuesday. "We are not happy with the Americans, the Kabul government and all parties who have not been honest with us," he said.
Karzai broke off bilateral talks with the Americans and threatened to boycott any peace process altogether after the Taliban opened the offices with a flag-raising ceremony for the "Islamic Emirate of Afghanistan" - the name of the country under Taliban rule.
The US State Department said that the closure of the office should not disrupt what it called a "challenging process".
"We believe that misunderstandings that arose in the context of the opening [of the office] should not stand in the way of moving forward on reconciliation if the Taliban wishes to do so," State Department spokeswoman Jen Psaki said.
"We'll continue to support and reiterate our call for that process to move forward."
The latest setback came as Afghan officials said a Taliban-planted bomb in the western province of Herat killed 17 civilians, and an Afghan soldier shot dead a Slovakian soldier at Kandahar airfield.
The New York Times also reported that the US was seriously considering speeding up the withdrawal of its forces because of frustration with Karzai.
The US President, Barack Obama, is committed to ending the US military involvement in Afghanistan by the end of 2014, though his administration has been negotiating with Kabul about leaving behind a "residual force".
"There has always been a zero option, but it was not seen as the main option," one senior Western official in Kabul told the newspaper. "It is now becoming one of them."
The roadside bomb in Herat killed 12 women, four children and one man travelling in a three-wheel minivan, officials said, adding that at least seven other passengers were wounded.
The Slovakian government confirmed that one Slovak soldier was killed and six were injured on Tuesday when an Afghan soldier opened fire in the latest "insider attack" to shake the NATO coalition.