Defense Secretary Donald H. Rumsfeld said today that the death toll among U.S. forces in Iraq is likely to reach 1,000 soon, but he played down the grim milestone by noting that thousands of Americans and people of other nationalities have already died in terrorism worldwide, and he warned that "the civilized world has to stay on the offensive."

According to a Washington Post tally based on Pentagon records, 997 U.S. service members have died in Iraq since the U.S. invasion was launched in March 2003. The list includes 248 deaths categorized by the Pentagon as resulting from "non-hostile" causes, such as accidents, but it leaves out three deaths of U.S. Defense Department civilian employees. Including those deaths, the Associated Press says the toll of 1,000 deaths has already been reached.

In a news briefing at the Pentagon, Rumsfeld expressed sympathy with Russians for the massacre of hundreds of people, many of them children, in a hostage-taking at a school in the southern Russian city of Beslan.

"Extremists seek to terrorize innocent men, women and children, whoever they are and wherever they may live," Rumsfeld said in his opening remarks. "There are really no free passes in this struggle, this war. There are no free passes for countries. There are really no free passes for individuals. And for that reason the civilized world has to stay on the offensive."

Noting that "taking the offense . . . has its cost," Rumsfeld said, "And soon the American forces are likely to suffer the 1,000th casualty at the hands of terrorists and extremists in Iraq. When combined with U.S. losses in other theaters in the global war on terror, we have lost well more than a thousand already."

Rumsfeld said, "It should be noted that the civilized world passed the thousandth casualty mark a long time ago. Hundreds were killed in Russia last week to be sure. And this week, of course, on September 11th, 2004, we remember the 3,000 citizens of dozens of countries who were killed on September 11th in 2001."

That date did not mark "the beginning of terrorism," he said. "And the war in Iraq has not created terrorism. International terrorists declared war on the civilized nations of the world sometime back. And over the decades, they have killed many thousands of Americans and citizens of other countries, as well."

The unprompted comments appeared aimed at blunting the impact of the 1,000th U.S. military death in Iraq, a milestone that could become an issue in the current presidential election campaign.

Air Force Gen. Richard B. Myers, chairman of the Joint Chiefs of Staff, said in the same news briefing today that the enemy in Iraq "is becoming more sophisticated in its efforts to destabilize the country." He said that "a recent spike" in casualty figures is attributable in part to an increase in suicide attacks, as well as more sophisticated small-arms assaults.

"Make no mistake, we will continue to pursue those who seek to disrupt progress in Iraq," Myers said, adding that "the more aggressive the tactics of the insurgency, the greater their loss of human life."

Asked about the approach of the 1,000th-death milestone, Rumsfeld said that while each loss of a U.S. service member looms large "from our standpoint," the number of deadly encounters pales by comparison with the "thousands of patrols" conducted every day by members of the U.S.-led coalition and the Iraqi security forces.

"If you take all of those patrols and look at the number of incidents, they are relatively small," Rumsfeld said.

He said the resistance in Iraq amounts to "a combination of terrorists, former regime elements and criminals that are being paid by terrorists or former regime elements."

In response to another question later in the briefing, Rumsfeld estimated that in the last month coalition and Iraqi forces "have probably killed" between 1,500 and 2,500 insurgents.

"Now is that a lot?" he asked rhetorically. "Yes. Does that hurt them? Yes. Is it a lot out of 25 million people in a country? No. Is it a lot when you've got borders that are porous and more can come in? No. But is the conflict, the offense, being effectively waged? The answer is yes. It is."

Myers said that although there are places in Iraq where U.S. forces do not conduct patrols, either alone or with Iraqi forces, these places "are all going to be dealt with on priorities that are developed by the Iraqi government and by coalition forces."

To that statement, Rumsfeld added that Iraqi interim Prime Minister Ayad Allawi and his government "fully understand that it is important that there not be areas in that country that are controlled by terrorists." He said, "For their country to succeed, they simply cannot over a sustained period of time have areas that are under the control of people who are violently opposed to that government."

Rumsfeld cautioned that as elections approach in Iraq and Afghanistan, rebels in both countries are likely to "increase the violence rather than decrease the violence."

Asked whether U.S. forces were "winning the peace in Iraq" even though they cannot enter some cities, Rumsfeld replied: "I think the phrase winning -- the U.S. military winning -- I think the question is ultimately: Are the Afghan people going to win back their country from the extremists? Are the Iraqi people going to win back their country with the vicious dictatorship and from the terrorists that are trying to take over their country? I think in both cases they will be successful."