Launching a new effort to rally support for the war in Iraq, President Bush on Monday acknowledged the dangers that U.S. troops face and vowed that their sacrifices wouldn’t be in vain.

“I understand how dangerous it is there,” he said. “I understand we’ve got kids in harm’s way, and I worry about their families. And obviously, anytime there’s a death, I grieve.”

The president’s sober assessment was part of a White House effort to reassure Americans that he’s on top of events in Iraq and is working to bring U.S. troops home. With polls showing growing dissatisfaction with the war, even some of Bush’s fellow Republicans have urged him to be more forthright about the difficulties there.

White House aides said the president planned a series of speeches and other events focusing on the stakes in Iraq and his strategy for success. His comments Monday contrasted with Vice President Dick Cheney’s assertion late last month that the Iraq insurgency is in its “last throes.”

Iraq is likely to be near the top of the agenda today when Bush meets with Senate Republicans at the White House. Some Republican lawmakers have become increasingly vocal about their differences with the president and his advisers.