Kerry Lands in Kabul amid Frayed Relations

U.S. Secretary of State John Kerry landed in Afghanistan on Monday on an unannounced visit, with relations badly frayed by Kabul's recent hostility to U.S.-led military efforts in the country.

Kerry is likely to face a testing meeting with President Hamid Karzai who has launched a series of verbal assaults on U.S. troops and their coalition partners.

"He will make clear that the U.S. will have an enduring commitment in Afghanistan that will last beyond transition and that there will always be bumps on the road," a U.S. official traveling with Kerry told reporters.

More than 11 years after the Taliban were ousted from power, international forces are withdrawing from Afghanistan and handing responsibility for fighting the Islamic insurgents to poorly-trained local police and army.

As the transition gathers pace, the United States and Afghanistan are also negotiating a strategic pact that will determine the U.S. presence in the country after the end of international combat operations next year.

One major cause of friction between Washington and Kabul was solved hours ahead of Kerry's arrival when a ceremony was held to mark the final transfer of the controversial Bagram jail from U.S. to Afghan control.

The drawn-out war is increasingly unpopular in the U.S., and Karzai triggered fury earlier this month when he accused the U.S. of working in concert with Taliban militants to justify keeping soldiers on foreign soil.

"Issues of security and sovereignty are always going to be difficult," the U.S. official traveling with Kerry said.

"But the most important thing is that we are honest to each other when there are differences between us, and you have seen some differences playing out recently."