President Bush (search) said Thursday that videotape threats from Al Qaeda's second-in-command will not drive the United States out of Iraq or the broader Middle East.

"We will stay on the offense against these people," Bush said of the comments by Aymen al-Zawahiri (search).

Al-Zawahiri threatened more destruction in London (search) and said in a videotape earlier Thursday that the United States would suffer tens of thousands of military dead if it does not withdraw from Iraq.

"They're terrorists and they're killers and they will kill innocent people ... so they can impose their dark vision on the world," Bush said as he stood alongside Colombian President Alvaro Uribe.

Their talks at Bush's ranch focused heavily on terrorism and the problem of narcotics trafficking.

Uribe said that both he and Bush consider the war against international terrorism a top priority of both their countries.

"The great enemy of Colombian democracy is terrorism...and our great partner in defeating it has been the government and people of the United States," Uribe said. "U.S. cooperation has been exemplary. It has gone beyond rhetoric. ... All democratic countries should know that."

Bush vowed continued U.S. aid to help Colombia fight narco-terrorism, and to enhance its economy and its economic institutions. "America will continue to stand with the people of Colombia," he said.

Uribe said more U.S. support was important and thanked Bush for seeking more aid from Congress.

"We cannot leave this task half finished," he said.

Bush also paid tribute to Marines who died over the past few days in bombings in Iraq, including a community from near Columbus, Ohio, which suffered heavy losses.

He said that the community of Brook Park "suffered mightily over the last couple of days."

"I hope they can take comfort in the fact that millions of their fellow citizens pray for them," he said.

During a question and answer session with reporters, Bush was asked about al-Zawahiri's videotaped warnings.

"The comments of the No. 2 man of Al Qaeda make it clear that Iraq is part of this War on Terror, and we're at war," Bush said.

"As I have told the American people, people like Zawahiri have an ideology that is dark, dim, backwards," the president said. "They don't trust, they don't appreciate women. If you don't agree to their narrow view of religion, you're whipped in the public square."

Bush said that al-Zawahiri "was a part of the team that attacked us on Sept. 11, 2001."

"Part of their goal is to drive us out of the broader Middle East: precisely what this Zawahiri said. He's threatening. They have come up against a nation that, one, will defend itself," Bush said.

"We will stay the course. We will complete the job in Iraq," he added.

After the news conference, Bush and Uribe toured the ranch in Bush's white pickup truck — a pastime that Bush likes to call "windshield ranching."