President Bush on Wednesday discounted Vladimir Putin's threat to retarget missiles on Europe, saying "Russia's not going to attack Europe."

Bush, in an interview with The Associated Press and other reporters, said no U.S. military response was required after Putin warned that Russia would take steps in response to a U.S. missile shield that would be deployed in Poland and the Czech Republic.

"Russia is not an enemy," Bush said, seeking not to inflame a heated exchange of rhetoric between Washington and Moscow. "There needs to be no military response because we're not at war with Russia. ... Russia is not a threat. Nor is the missile defense we're proposing a threat to Russia."

Bush spoke before heading off to lunch with German Chancellor Angela Merkel, who is hosting the annual meeting of the world's seven richest industrial democracies and Russia. Merkel has made global warming the centerpiece of her G-8 leadership and is pushing for specific targets for reducing carbon emissions.

The meeting is being held under tight security on the Baltic Sea coast in northern Germany. Police used water cannons to scatter an estimated 10,000 demonstrators who swarmed a seven-mile fence that encircles the site. At one section, hundreds of protesters chanted "Peace" and "Free G-8! Free G-8!"

Bush, who met with reporters for nearly an hour in a sun-drenched garden, also discussed Iran, the suffering in Darfur, global warming and this week's sentencing of a former White House aide.

The president said he would like to see other countries follow the United States in taking steps against the government of Sudan to stop the misery in Darfur.

"I'm frustrated because there are still people suffering and the U.N. process is moving at a snail's pace," Bush said.

Bush announced tighter U.S. sanctions on Sudan last week. He also is seeking a U.N. resolution to apply new international sanctions against the Sudanese government.

On climate change, Bush said he would not give ground on global warming proposals that would require mandatory caps on greenhouse gas emissions. Instead, he backed his own idea for the United States and other nations that spew the most greenhouse gases to meet and — by the end of next year — set a long-term strategy for reducing emissions.

Merkel has proposed a "two-degree" target, under which global temperatures would be allowed to increase no more than 3.6 degrees Fahrenheit, before being brought back down. Practically, experts have said that means a global reduction in emissions of 50 percent below 1990 levels by 2050. Merkel supports a global carbon-trading market as one tool.

But Bush wants to bring India, China and other fast-growing countries to the negotiation table. He envisions that each country will set their own goals, and decide whether they should be binding. The president said his plan addresses "life after" 2012, the expiration date for the Kyoto Protocol, which the United States has not endorsed.

Merkel put a good face on her talk with Bush about issues such as combatting poverty in Africa. But their debate on global warming seems unlikely to produce the kind of hard targets she and others have advocated. "We started here on a very good footing," she said.

Bush also met with Japan's new prime minister Shinzo Abe and discussed North Korea's pledge to close its sole nuclear reactor in exchange for economic aid and political concessions. "There is a common message here and that is: We expect North Korea to honor agreements," Bush said.

While North Korea topped Bush's talks with Abe, and hers with other leaders before the evening's official opening of the summit, the president's plan to deploy an anti-missile radar system in the Czech Republic and 10 interceptor missiles in Poland is likely to be a key topic in Bush's meeting Thursday with Putin.

Asked if he anticipated a tense encounter, Bush replied "Could be. I don't think so ... I'll work to see that it's not a tense meeting."

Putin has accused the U.S. of starting a new arms race and said if the U.S. pressed ahead with its plan, Russia would revert to targeting its missiles on Europe as it did during the Cold War. China joined Russia in saying the missile defense plan could touch off a new escalation in nuclear weapons.

The move to put the missile defense shield in former Warsaw Pact nations — purportedly as a defense against a future missile launch from Iran — clearly fanned Putin's anger.

Bush cited Iranian President Mahmoud Ahmadinejad's declaration that it was "too late" to stop Iran's nuclear program as justification for the U.S. missile defense system. "Therefore, let's build a missile defense system," Bush said, adding that it was time to return to the U.N. Security Council to tighten pressure on Iran to give up its suspected weapons program.

Bush also has angered Putin in the past by criticizing Russia's spotty progress on democratic reform and human rights — a theme Bush expressed in a speech just one day ago. Bush said that despite all the problems, the United States has a friendship with Russia. He suggested Putin's recent rhetoric could be calculated mostly for internal political consumption in Russia.

"There will be disagreements," said Bush, who has invited Putin to meet him in July in Kennebunkport, Maine, the home of his father, former President George H.W. Bush. "That's the way life works."