NATO's top commander on Thursday urged allied nations to send reinforcements to southern Afghanistan, where resurgent Taliban militants are inflicting heavy casualties on foreign forces and have captured a remote town for the second time in two months.

A NATO spokesman said alliance forces also killed 21 militants in air and ground strikes Thursday in southern Kandahar province's Panjwayi district, the scene of a large-scale anti-Taliban operation that has left at least 270 insurgents dead with the latest fatalities.

Gen. James L. Jones said after a trip to Afghanistan that the coming weeks could be decisive for thousands of troops fighting in the south of the country amid the worst upsurge in violence since the hard-line Taliban regime's ouster in late 2001.

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He said in Belgium that NATO needed "additional insurance in terms of some forces that can be there, perhaps temporarily, to make sure that we can carry the moment."

NATO has been surprised since moving into the region by the intensity of Taliban attacks and by insurgents' willingness to stand and fight rather than hit NATO forces and run, he said.

NATO took command of southern Afghanistan from a U.S.-led coalition on Aug 1.

Jones said he was disappointed by some NATO nations' lack of commitment to the efforts in southern Afghan provinces.

But he said he remained confident that a meeting with top generals from the 26 NATO nations Friday and Saturday in Warsaw, Poland, would muster helicopters, transport planes and several hundred "flexible" reserve troops able to move quickly around the region to support NATO forces on the ground.

"In the relatively near future, certainly before the winter, we will see this decisive moment in the region turn in favor of the troops that represent the government," said Jones.

Britain, Canada and the Netherlands have taken lead roles since NATO took command in the south, pumping in around 8,000 troops. The alliance claims to have inflicted grave insurgent losses, including more than 250 in an offensive near Kandahar city since the weekend.

But at least 35 British and Canadian soldiers have died within 38 days, and militants show no sign of giving up.

Late Wednesday, Taliban militants reclaimed the southern Helmand provincial town of Garmser after police fled their compound there for the second time since July, said local police chief, Ghulam Nabi Malakhail.

NATO spokesman Maj. Scott Lundy confirmed clashes in the town but said he was unaware that police had left.

Taliban forces held Garmser, a town of about 50,000 people, for two days in July, after defeating 40 poorly armed police in 16 days of fighting. U.S., British, Canadian and Afghan ground troops won the town back and left it to reinforced Afghan security forces.

The 21 suspected Taliban were killed as NATO forces continued targeting militant hide-outs in campaign dubbed Operation Medusa that started Saturday, said Maj. Scott Lundy.

Fourteen of the militants were killed in a NATO airstrike, while the seven others died in separate clashes with ground forces, Lundy said.

In Kabul, Pakistani President Gen. Pervez Musharraf acknowledged that Al Qaeda and Taliban militants cross from Pakistan to launch attacks inside Afghanistan, but denied his government sponsored them.

"You blame us for what is happening in Afghanistan," Musharraf told Afghan government and army officials and lawmakers. "Let me say neither the government of Pakistan nor ISI (Directorate of Inter-Services Intelligence) is involved in any kind of interference inside Afghanistan."

Musharraf's speech came a day after he and Afghan President Hamid Karzai resolved to cooperate to fight the "common enemy" of terrorism and extremism. Musharraf left for Pakistan after his speech Thursday.

The Afghan Defense Ministry's chief spokesman said his country needs NATO reinforcements in the short term, but more help to rebuild its national army in the long run.

"We welcome and appreciate any NATO reinforcements to southern Afghanistan, which is necessary for the peace and stability of the country," said Gen. Zahir Azimi. "But in the long term, NATO should focus on building up the Afghan National Army."

Afghanistan currently has about 30,000 soldiers in its army and 60,000 lesser-equipped police. Its defense minister believes a Western plan to increase the army's size to 70,000 is insufficient and that at least double that number is needed.

NATO is considering whether to move forward on with plans to take command of the east of Afghanistan, currently under the U.S.-led coalition, before the end of the year. That would raise the number of NATO forces in country to around 24,000. The alliance also leads efforts in the north and west of the country.

In violence Thursday, Afghan police killed four Taliban fighters in southeastern Paktiya province, said provincial police chief Gen. Abdul Anan Roufi. Three Taliban were arrested and three others fled, he said.

A roadside bomb killed two police and wounded four in neighboring Paktika province late Wednesday, said Sayed Jamal, spokesman for the provincial governor. One Taliban was killed and seven wounded in two clashes in Ghazni province, south of Kabul, a provincial official said.