President Bush said Wednesday he didn't expect to get unanimous support at home for the decision to invade Iraq and said failure there "is not an option."

Talking to reporters on the White House South Lawn after a meeting with a group of governors who have returned from a visit to Iraq and Afghanistan, Bush said he thanked the state chief executives for "sending a message from home that we care ... we appreciate the fact that people are willing to make sacrifices."

"I assured them that our goal in Afghanistan and Iraq is victory and victory will be achieved when there is a democracy in both countries," and those democracies can sustain and defend themselves, he said.

"We fully recognize that the Iraqis must step up and form a unity government so that those who went to the polls to vote recognize that a government will be in place to respond to their needs," he said.

"We understand full well that the political process in Iraq must occur soon," the president added. "I don't expect everybody to agree with my decision to go into Iraq. But I do want the people to understand, the American people to understand, that failure in Iraq is not an option."

Success there will "begin to lay the foundation of peace for generations to come," Bush said.

"I assured the governors that the United States will complete the mission," he said.

Gov. Mitch Daniels of Indiana said he was heartened by what he saw there, and said that "everything that can be done is being done and on a daily basis" to help protect the U.S. troops in Iraq.

Daniels said the troops' commitment to the mission in Iraq "is unanimous. They believe they are doing something important."

West Virginia Gov. Joe Manchin said the troops there are "committed to getting the job done. ... It was so good to see them being in such high spirits."