Pakistan will erect fencing to reinforce parts of its porous mountain border with Afghanistan, President Gen. Pervez Musharraf said Friday, while acknowledging for the first time that some outgunned Pakistani frontier guards have allowed militants to cross.

However, Musharraf denied that the Pakistani army or intelligence service was actively supporting Taliban militants, who have stepped up attacks in Afghanistan over the past year, sparking fighting that has killed thousands.

"There is no question of anyone abetting, but there are people at the tactical level who turn a blind eye ... and that needs to be corrected," Musharraf told reporters at his army office.

Musharraf had proposed fencing and mining the border under Western pressure to do more to prevent Taliban and Al Qaeda militants from using Pakistan's wild borderlands as a base for operations against Afghan and foreign troops on the other side.

Bolstering Pakistan's ability to combat the militants, the United States delivered eight attack helicopters to the key U.S. ally Friday. The Cobra AH1-F helicopters, specially equipped for nighttime operations, were part of a $50 million deal for a total of 20 refurbished helicopters.

"We understand and appreciate the very real sacrifices that Pakistan is making in the war on terror," U.S. Ambassador Ryan Crocker said at the handover ceremony.

Washington agreed last year also to sell F-16 fighter planes to Pakistan. However, legislation introduced in January in Congress would tie American military aid to Pakistan's performance in countering militants.

Crocker said he thought "such conditionality would be counterproductive."

In the border plan, a first phase would see fencing erected along seven or eight locations — a total of 22 miles along Pakistan's northwest frontier — and would take "a few months," Musharraf said. "The decision has been taken and movement of logistics must be taking place at the moment."

He said mines would not be used in the initial phase because of concerns raised by the international community. However, he said plans for a second phase still foresaw using both fencing and mines to secure 150 miles of the frontier further south, in Pakistan's Baluchistan province.

"No one has the right to criticize unless they come up with an alternative solution ... if there is no (other) solution, we will do it our way," Musharraf said.

There was no immediate comment from Afghan officials Friday.

Musharraf also repeated Pakistani complaints that it is being used as a scapegoat for the resurgence of Taliban-led militants. Afghan authorities and U.S. and NATO-led troops in Afghanistan shared responsibility for the border, he said.

"A misperception is being created that the resurgence of Taliban is from Pakistan. This is absolutely wrong. The resurgence of the Taliban is in Afghanistan, but some support goes from Pakistan," he said.

Pakistan had helped foreign forces "eliminate" Mullah Akhtar Mohammad Osmani — a top lieutenant of Taliban leader Mullah Omar — in Afghanistan's southern Helmand province, just across the border from Pakistan, Musharraf said.

U.S. military officials in Afghanistan have privately said that Pakistan helped them locate Osmani, who died in an airstrike in December. He was the highest-ranking militant killed there since the ouster of the hardline regime in 2001.

Musharraf, a key ally in the U.S.-led war on terror, revealed that three times a top Taliban military commander, Mullah Dadullah, had been in Pakistan but evaded capture.

"Thrice we tried to get him, and thrice we failed," he said, adding that the attempts were the fruits of intelligence cooperation with Pakistan's anti-terror allies.

While he denied any official Pakistani collusion with militants, Musharraf acknowledged that there had been cases of security forces at isolated posts at the frontier letting fighters pass.

He cited an example of two guards, located 500 yards from their section base, being outnumbered by around 20 highly trained and motivated Al Qaeda militants.