KANDAHAR - US Defence Secretary Chuck Hagel told American troops on Sunday that he supports a NATO force in Afghanistan after 2014, as Washington and President Hamid Karzai wrangle over a stalled security pact.

nHagel travelled to bases in south Afghanistan to meet troops a day after further tensions arose over the Bilateral Security Agreement (BSA), which would allow some NATO forces to stay in the country after most combat troops withdraw next year.

"I believe there is a role for our coalition partners and the United States, but that depends on the Afghan people," Hagel told soldiers in a question-and-answer session at Camp Bastion in Helmand province. "If the people of Afghanistan want to continue that relationship, then we will." US commanders were looking at "a new phase for our mission to train, assist, advise and counter-terrorism", he added.

Meetings with Karzai have been customary over the years for Pentagon chiefs, but Hagel had no plans to meet the Afghan president during his weekend visit. "I have hope that the BSA will get signed," he said.

Since President Barack Obama's National Security Adviser Susan Rice and top diplomat John Kerry had already had frank discussions with Karzai urging him to sign the security agreement, Hagel said on Saturday there was no point in him repeating the US position. "There's not much I can add in a meeting with President Karzai to what's already been said," he said. Hagel did meet the Afghan defence minister, Bismillah Khan Mohammadi, who assured him the security agreement would be signed in "a timely manner".

Afghan President Hamid Karzai agreed on a cooperation pact with Iran on Sunday, an Afghan official said, while continuing to resist signing a long-term security agreement with the United States. Karzai struck the deal with Iranian President Hassan Rouhani in Tehran in a move that will be greeted with suspicion by his U.S. ally, which is trying to convince him to sign the security accord governing any post-2014 U.S. presence in Afghanistan. "Afghanistan agreed on a long-term friendship and cooperation pact with Iran," Karzai's spokesman Aimal Faizi said. "The pact will be for long-term political, security, economic and cultural cooperation, regional peace and security." He said a formal document would be prepared and signed soon.

In August Afghanistan signed a strategic cooperation pact with Iran covering mainly security issues, but Faizi said the proposed new agreement would have much broader scope. Many Afghans believe such a bargain with Iran, at odds with the United States since the 1979 Islamic revolution, may harm Afghanistan's uneasy relationship with its Western allies. The U.S. bilateral security pact is a decade-long agreement that would provide a legal basis for about 8,000 U.S. troops to stay on after the NATO-led combat mission ends next year.

Its future was thrown into doubt last month when Karzai said he would sign only if new conditions were met, and then only after Afghanistan's elections in April.

Iran has long opposed NATO's presence in Afghanistan and is the only country to have asked Karzai not to sign the agreement. Rouhani reinforced that message after meeting Karzai. "All foreign troops should be withdrawn from the region," he posted on his official Twitter account. "(The) security of Afghanistan should be entrusted to the Afghan people."