U.S. president-elect Barack Obama told Afghanistan's leader he will dedicate more U.S. aid and military power to the region's fight against extremist groups once he takes office, the Afghan presidential office said Sunday.

The telephone conversation between Obama and President Hamid Karzai on Saturday was the first reported contact between the two, although Obama spoke to at least 15 other world leaders in the three days after winning the U.S. presidential election.

A senior Afghan official dismissed the idea that anything should be read into the delay, calling Obama a "busy man."

"I think it was purely a logistical issue, nothing of political significance," said the adviser, who agreed to discuss the phone call only if not quoted by name because he wasn't authorized to talk about it.

Karzai's spokesman did not respond to requests for comment. A call to an Obama spokesperson was not immediately returned Sunday.

The leadership change from President George W. Bush could present Karzai with new challenges in his relationship with the U.S. Obama has chided Karzai and his government in the past, saying it had "not gotten out of the bunker" and helped to organize the country or its political and security institutions.

The United States has about 32,000 soldiers in Afghanistan, a number that will be increased by thousands next year. The current NATO commander, U.S. Gen. David McKiernan, has requested an additional 20,000 troops.

Fighting terrorism and the insurgency "in Afghanistan, the region and the world is a top priority," Karzai's office quoted Obama as saying.

"The region" is commonly used by Afghan officials to refer to neighbouring Pakistan, where Karzai and Bush administration officials have longed complained that Taliban and al-Qaeda militants have bases to support their attacks in Afghanistan.

Obama's reported pledge to step up military help likely pleased Karzai, whose relations with Pakistan are testy because of his accusations that the Pakistani intelligence service supports the Taliban in bombings in Afghanistan. Pakistan's government flatly denies the charge.

Obama also has expressed frustration with Pakistan over its failure to quell Islamic militants on its territory. During the presidential campaign, he said, "If Pakistan cannot or will not act, we will take out high-level terrorist targets like [Osama] bin Laden if we have them in our sights."

NATO, Pakistani troops get along despite some incidents

Last week, American troops fired artillery at insurgents, attacking their position from inside Pakistan's volatile tribal region. Since mid-August, U.S. forces are suspected of using drone aircraft to launch at least 20 missiles at targets on Pakistani territory, killing dozens of alleged extremists while angering the Pakistani government.

Still, over the past month, NATO and Pakistani forces have been co-operating in Operation Lion Heart, a series of complementary operations that involve the Pakistani army and its paramilitary Frontier Corps on one side of the border and NATO on the Afghan side.

The top spokesman for the NATO-led force in Afghanistan, Brig. Gen. Richard Blanchette, said Sunday that co-operation among Afghan, NATO and Pakistani troops is "the best it has ever been."

"You finally have those who are really conducting the operations, the soldiers who know exactly where on the other side the operations are happening, so you can have a movement which you could compare to the movement of a hammer and an anvil," Blanchette said.

French Foreign Minister Bernard Kouchner said in remarks televised Sunday that he has doubts about Obama's plans to fight Islamic militants in Afghanistan. He said an increase in troop numbers would only work "in precise areas with a precise task."

Kouchner said France believes military power alone won't stabilize the situation in Afghanistan and that international troops should help the Afghan people "take matters into their own hands."

Karzai faces his own election challenge next year and will need the support of the new U.S. administration to help keep his standing with Afghan voters, who are increasingly tired of government corruption and worsening violence seven years into the war against the Taliban.

One of the leaders of Afghanistan's opposition parties, former president Burhanuddin Rabbani, said Sunday that his National Front party is demanding that the election be held no later than May, as stipulated in the country's constitution.

The date of the election has not yet been announced, but officials with the election commission contend the ballot cannot take place before August or September because of weather concerns and logistics. The UN is now helping to register Afghan voters based on that timetable.