Bucharest: US President George W. Bush yesterday urged his Nato allies to commit more troops for the anti-Taliban mission in Afghanistan and called for more cooperation on the war in Iraq.

"This enemy [Al Qaida] remains dangerous, and that's why our alliance is so important to protecting innocent people," Bush said. "Whatever the cost, however difficult, we must win," he said at a news conference in Romania, hours before the official opening of the largest summit since the military alliance was established in 1949.

Bush told reporters at a later event with his Romanian hosts: "We expect our Nato allies to shoulder the burden necessary to succeed."

On Iraq, Bush kept up his defence of the five-year war, which has damaged credibility with America's friends and foes alike. Bush said a US troop buildup in Iraq had yielded significant security progress. "There's tough fighting ahead, but the gains from the 'surge' we have seen are real," he said.

Bush also appealed to Russia to drop opposition to a missile defence shield.

"To ensure that we win, France is sending additional forces to Afghanistan. The United States is deploying an additional 3,500 marines. Romania is adding forces, as are several other allies," Bush said.

- With inputs from Reuters