Defense Secretary Donald Rumsfeld said he believes Iraq has chemical and biological weapons that are "more lethal and dangerous today than they would have been in '91, but I don't know that for sure." 

Addressing the conservative Hoover Institute, Rumsfeld noted that Iraq sent some of its warplanes out of the country during the 1991 Gulf War, and he suggested Saddam might do the same with weapons in the current situation. 

Speaking later in an interview with the pan-Arab television channel Al-Jazeera, Rumsfeld said Saddam had only three choices: to cooperate with the inspectors or do nothing or leave. 

Saddam was risking war, Rumsfeld said in the interview, which was broadcast live from the Pentagon. Al-Jazeera, noted for its reach and credibility among Arab viewers, said the defense secretary had requested the interview. 

Reached after the Senate hearing, Levin said Shinseki's estimate of an occupation force was "very sobering and I would hope the American public would have the opportunity to read that testimony." 

"It sounded as though almost as large a contingent would need to remain as was there to begin with," Levin said. 

He said he wanted to review the transcript himself to make sure he understood Shinseki comments completely. 

Army spokesman Col. Joseph Curtin said later that Shinseki was only giving a rough estimate. 

Pentagon officials have said that U.S. forces massed in the region number about 200,000, about half of them Army. 

Responding to concerns raised by the committee chairman, Sen. John Warner, R-Va., Shinseki and Gen. John P. Jumper, the Air Force chief of staff, said some of their forces, particularly special operations troops, were being stretched thin by the demands made on them. In addition to the buildup in Iraq, special forces have been deployed in the Afghanistan region, the Philippines and Colombia. 

"They are stressed," Shinseki said. "We are using them on multiple missions that a few years ago was not anticipated." 

Navy and Marine leaders said the problems weren't as great with their troops. 

"Am I concerned about the next 60 to 90 days? No,I am very confident," said Adm. Vern Clark, chief of Naval operations. 

Sen. Edward Kennedy, D-Mass., questioned whether the administration was so focused on Iraq, it wasn't paying sufficient attention to other threats, such as North Korea's nuclear program and pursuit of Osama bin Laden, despite its insistence that it could fight two wars simultaneously. 

"It appears to me that we developed and sustained a two-war military to only have it run by an administration with a one-war attention span," he said. 

Meanwhile, a White House envoy entered northern Iraq on Tuesday to attend a conference of opposition leaders as Kurdish lawmakers warned of violence if Turkey invades Iraq in the event of a U.S.-led war. 

Zalmay Khalilzad, the U.S. representative to the Iraqi opposition, crossed from Turkey into the Kurdish autonomous zone of Iraq to take part in discussions on the future of Iraq should Saddam be overthrown, local officials said. 

Khalilzad's visit comes amid increased regional tensions as war looms and Turkey's parliament considers a bill that would authorize sending its troops into northern Iraq in the event of war. 

U.S. military officials said American warplanes bombed surface-to-surface missile systems in northern and southern Iraq on Tuesday and also attacked surface-to-air missiles in southern Iraq. 

The U.S. planes struck the missile systems because they threatened coalition forces that are enforcing no-fly zones and assembling in Kuwait for a possible war with Iraq, military statements said. The strikes were the most extensive on a single day since the U.N. Security Council in November passed its latest resolution demanding that Iraq disarm.