The top US general in Afghanistan expressed dismay on Sunday at remarks by President Hamid Karzai, who suggested that Washington benefited from Taliban attacks on his country.
Karzai's remarks, delivered during the first visit by new US Defense Secretary Chuck Hagel, further strained already fraught ties between Karzai and the Western allies who are fighting to protect his government from insurgents.
The United States still has 66,000 troops in Afghanistan, down from almost 100,000 two years ago at the height of a surge ordered by President Barack Obama. Washington intends to withdraw most of them by the end of next year but wants to negotiate a continued, smaller presence.
Speaking a day after two Taliban bomb attacks that killed 17 people, Karzai said the bombings served Washington's aim of trying to convince Afghans that US forces were needed.
"Those bombs that went off in Kabul and Khost were not a show of force to America. They were in service of America. It was in the service of the 2014 slogan to warn us if they (Americans) are not here then Taliban will come," Karzai said.
"In fact those bombs, set off yesterday in the name of the Taliban, were in the service of Americans to keep foreigners longer in Afghanistan," he said in a speech.
Karzai's remarks drew a rebuke from General Joseph Dunford, the head of US and NATO forces in Afghanistan.
"We have fought too hard over the past 12 years, we have shed too much blood over the past 12 years, we have done too much to help the Afghan security forces grow over the last 12 years to ever think that violence or instability would be to our advantage," he told reporters.
Of Karzai's remarks, he added: "I'll let others judge whether that's particularly helpful or not at the political level."
Karzai has a history of making inflammatory statements that exasperate Washington. His comments have become increasingly bitter as the withdrawal date has approached.
Karzai's government also alleged on Sunday that US-led forces and Afghans working with them were abusing and arresting university students. Karzai issued an executive order banning foreign troops from entering all education institutions.
The United States helped install Karzai in power in 2001 after driving the Taliban out of Kabul in a bombing campaign, in retaliation for the Taliban shielding al Qaeda leader Osama bin Laden. US troops have fought since then to help prevent the Taliban from returning, but many in Afghanistan resent the presence of foreign forces and question their aims.
The Taliban have for years demanded the withdrawal of foreign forces and have never suggested that they should stay.
The issue of US troop levels after most US-led NATO combat troops withdraw by the end of 2014 will be one of the main subjects on the agenda at talks between Karzai and Hagel, who is making his first foreign trip as Pentagon chief.
A joint news conference that had been scheduled for them was cancelled because of security worries, a US official said.
One of Saturday's bombings, a suicide attack which killed nine people, took place outside the defence ministry where Hagel's meetings with his Afghan counterpart were supposed to take place. A US official said the venue for Hagel's meetings with Afghan officials had been changed.
Among many sources of friction, Hagel's visit coincides with the passing of a deadline imposed by Karzai for US special forces to leave the province of Wardak, after Karzai accused them of overseeing torture and killings in the area.
US forces have denied involvement in any abuses and a NATO official said on Saturday that US special forces were still operating in Wardak. Hagel has sounded hopeful that a deal could be reached on their continued deployment.
Karzai also said the Taliban and the United States had been holding talks in the Gulf Arab state of Qatar on a "daily basis", further fuelling his suggestion that Washington and the militants were working at common purposes.
The militant group and Washington both denied they had resumed efforts on dialogue, which stalled a year ago.
The US government has said it is committed to political reconciliation involving talks with the Taliban, but progress would require agreement between the Afghan government and the insurgents.
"This is simply incorrect," said a US official, who declined to be identified, when asked about Karzai's remarks about the talks.
The Taliban spokesman in Afghanistan, Zabihullah Mujahid, also denied that negotiations with the United States had resumed and said no progress had been made since they were suspended.
"The Taliban strongly rejects Karzai's comments," he said.
The Kabul government has been pushing hard to get the Taliban to the negotiating table before foreign troops withdraw.
Afghan officials have not held direct talks with the militants. US diplomats have been seeking to broaden exploratory talks with the Taliban that began clandestinely in Germany in late 2010 after the Taliban offered to open a representative office in Qatar.
Regional power Pakistan indicated a few months ago that it would support the peace process by releasing Afghan Taliban detainees who may help promote the peace process. But there have been no tangible signs the move advanced reconciliation.