Iran has given political and material support to Afghan President Hamid Karzai's Western-backed government, but it also may have aided the Taliban guerrillas as a way of hedging its bets inside its eastern neighbor, NATO's top general here suggested Monday. US Army Gen. Dan McNeill, in an interview with The Associated Press, said Taliban fighters were showing signs of better training, using combat techniques to pin down US Special Forces soldiers comparable to "an advanced Western military." Iran's possible role in aiding insurgents has been a hotly debated topic in Iraq, and there were allegations from some Western and Persian Gulf governments last month that the Islamic government in Teheran was secretly bolstering Taliban fighters in Afghanistan. "In Afghanistan it is clear that the Taliban is receiving support, including arms from ... elements of the Iranian regime," British Prime Minister Tony Blair wrote in the Economist on May 31. Iran - already criticized by the West for a number of issues including its nuclear program - hotly disputes the accusation, saying it is part of a broad anti-Iranian campaign and that it makes no sense for a Shi'ite-led government like itself to assist the fundamentalist Sunni movement of the Taliban. McNeill, the commander of 36,000 troops in NATO's International Security Assistance Force, said the indications cut both ways. There is "ample evidence" Iran is helping the Karzai government, particularly with road construction and electricity in western Afghanistan, but Iran may also have helped the Taliban and other political opponents of Karzai, he said. "So what does that add up to?" McNeill said. "It makes me think of a major American corporation that will give political campaign money to three or four different candidates for president of the United States. ... This corporation wants to be aligned with whoever comes out on top." McNeill, a 60-year-old four-star general from North Carolina who has fought in most American conflicts since Vietnam, said he had no hard evidence that the Iranian government has helped the Taliban. He said munitions, particularly mortar rounds, "clearly ... made in Iran" have been found on the battlefield in Afghanistan, but said that does not prove that the Iranian government is formally involved in aiding Taliban fighters. "If I had the information, I would have no reservation about saying it," he added. In a separate interview Monday, Iran's ambassador to Afghanistan denied his government was helping the Taliban. "This is not correct," Mohammad R. Bahrami said at Iran's Kabul embassy. "The return of extremism in Afghanistan will affect not only Afghanistan and the region, but the entire world." Bahrami said there was no evidence of Iranian support for the Taliban and that the US and Britain were making claims only to "justify their failures" in Afghanistan, such as the increasing opium poppy production and the Taliban's resurgence. Whether or not Iran is assisting the Taliban, violence is on the rise in Afghanistan, with insurgents launching more suicide and roadside bomb attacks this year than the record violence seen in 2006. More than 2,200 people have been killed in insurgency-related violence this year, according to an AP count based on US, NATO and Afghan officials. McNeill said the NATO forces under his command had launched a successful offensive this spring against insurgents, but he acknowledged that Taliban militants were showing signs of increased training. For instance, they advanced on US Special Forces in recent months after launching ambushes in tight terrain between high ground and a river, a complex military maneuver McNeill termed "surprising." "We have now seen them shoot and maneuver a couple times in ways we haven't seen before. Where that's coming from I'm not exactly certain," McNeill said. "But they have used some versions of fire and maneuver that makes one think of an advanced Western military." McNeill said he didn't have any information indicating conclusively that fighters in Afghanistan and Iraq were coordinating their efforts, but he wouldn't rule it out as a possibility. NATO forces gained a major victory in Afghanistan last month with the killing of Mullah Dadullah, deemed the top Taliban commander in the country. McNeill said Dadullah had attained "iconic" status among some Afghans, although his reputation had begun to wane after the distribution of videos showing his participation in beheadings of enemies and his encouraging a 12-year-old boy inside Pakistan to behead an alleged spy. While withholding details about how Dadullah was tracked down, McNeill said it was the "ego" of the Taliban commander that led to his death. "It was my view that any of these Taliban leaders, especially Dadullah, if they ever left their sanctuaries, especially if they came into Afghanistan, that their egos would be their undoing. In Dadullah's case that was a large part of it," McNeill said, alluding to Pakistan as Dadullah's sanctuary. McNeill painted an optimistic picture of the development of the new Afghan National Army, now approaching the fifth anniversary since its first battalions were trained. The Afghan army has made "tremendous strides" and was taking the lead in a new operation in Ghazni province, he said. Recruitment is up from 600 soldiers a month last year to more than 2,000 a month this year, McNeill said. "When I see how they are moving and shooting on the battlefield today, I realize how far they have come and how more advanced they are. That does not mean game over, time for us to go home," he said. "But I think that quite possibly the fighting season next year, maybe some fighting units will be operating independently." McNeill said NATO forces had slightly reduced the number of insurgents flowing into Afghanistan from Pakistan. He gave no details. "We have stemmed it a tad. Have we stemmed it greatly? I'm not in a position to say that's the case," he said. "Do I continue to be worried about what's coming over the border? The answer is yes."