KABUL, Afghanistan - Several thousand foreign fighters have poured into Afghanistan to bolster the Taliban insurgency, the country's defense minister said yesterday as he called for more international troops.

The remarks come as the United States debates whether to substantially increase its forces in Afghanistan or to conduct a more limited campaign focused on targeting al-Qaeda figures - most of whom are believed to be in neighboring Pakistan.

The minister's comments hit on a key worry of the United States - that not sending enough troops to Afghanistan will open the door again to al-Qaeda. They also suggest that the Afghan government is nervous about the U.S. commitment amid talk of changing the strategy and a surge in violence in recent months.

An American and two Polish soldiers were killed by bombs in the latest violence reported by NATO forces.

"The enemy has changed. Their number has increased," the defense minister, Gen. Abdul Rahim Wardak, told lawmakers in a speech. He said that about 4,000 fighters, mostly from Chechnya, North Africa, and Pakistan, "have joined with them and they are involved in the fighting in Afghanistan."

He gave no time frame for the increase he cited in foreign fighters.

Wardak said that Afghan intelligence services had asked for more international forces to cope with the foreign threat, and the minister's spokesman said Wardak backed the call.

U.S. military officials said they could not immediately comment on the claim of a recent influx of foreign fighters.

Afghanistan's interior minister, who also spoke to parliament, endorsed a strategy promoted by the U.S. commander, Gen. Stanley McChrystal, to focus on protecting civilians rather than simply killing insurgents. "If the target of this fight is only killing the Taliban, we will not win this war. If it is saving the Afghan people, then we have a possibility," Interior Minister Hanif Atmar said.

The strategy debate in the United States has been complicated by the still-undecided Afghan presidential election, which has raised doubts about whether there will be reliable, credible Afghan leadership to cement any military gains. Results from the disputed August vote have been delayed because of widespread allegations of fraud.

A U.N.-backed fraud investigation panel was analyzing data yesterday from an audit and recount of polling stations with suspect results. Results from about 13 percent of the country's polling stations hang in the balance - enough to swing the result from an outright win by President Hamid Karzai to a forced runoff.

Election officials have said they expect to announce final results by the end of this week.

The weeks of waiting have been dogged by accusations of wrongdoing between candidates and even within the U.N., which has advised on the vote and whose appointees dominate the fraud investigation panel. The second-in-command at the United Nations in Afghanistan, American Peter Galbraith, was fired last month after a dispute with his boss about how to investigate alleged fraud.