American military successes in Iraq have prompted growing numbers of well-trained "foreign fighters" to join the insurgency in Afghanistan instead, the Afghan defense minister said. The minister, Gen. Abdul Rahim Wardak, said at a news conference that the increased flow of insurgents from outside Afghanistan had contributed to the heightened intensity of the fighting here this year, which he described as the "worst" since the American-led forces toppled the Taliban government in 2001. American commanders have said that overall violence here has increased by 30 percent in the past year and have called for more troops. The defense minister said that "the success of coalition forces in Iraq" had combined with developments in countries neighboring Afghanistan to cause "a major increase in the number of foreign fighters" coming to Afghanistan. "There is no doubt that they are better equipped than before," he said. "They are well trained, more sophisticated, and their coordination is much better." His reference to neighboring countries appeared to mean Pakistan, where Islamic militants with bases in tribal areas along the border have intensified their operations, both inside Pakistan and in support of the insurgency in Afghanistan. American commanders have said that most of the foreign fighters operating in Afghanistan are Pakistanis, Arabs, or from Muslim countries and communities in Central Asia and the Caucasus, including Chechens. But a great majority of the insurgents here are Afghans. American commanders have noted that some militant Islamic Web sites have been encouraging fighters to go to Afghanistan rather than Iraq, where rebel operations have been sharply reduced in the past 18 months. Recent postings to some sites have celebrated the rising tempo of the insurgency here, and referred to the appeals for more soldiers and growing concerns among NATO nations that contribute troops.