HEILIGENDAMM, Germany (AP) – President Bush said he hoped to convince Russian President Putin on Thursday that their dispute over an American missile defense system is not an issue “to be hyperventilating about.”

Messrs. Bush and Putin are seeing each other for the first time here since their dispute over American plans for a missile defense system in Eastern Europe flared into Cold War-style rhetoric. They sit down later Thursday on the sidelines of a summit of the world’s eight major industrialized democracies being held at this seaside resort.

Relations have slid to their lowest point in decades, a point underscored Wednesday night when Mr. Putin’s spokesman, Dmitri Peskov, said Russia still regards American arguments that the shield targets a potential Iranian nuclear weapon, not Russian ones, as “insufficient explanations.”

Mr. Putin has warned that a new shield could require Russia to retarget missiles toward Europe or take other buildup measures. Bush administration officials have tried to tamp down Russia’s anger, arguing it is obvious the defense system isn’t aimed at Russia because of Moscow’s huge arsenal of nuclear rockets.

“A missile defense system cannot stop multilaunch regimes. … The fact is that you can’t stop 2-3-4-5 missiles,” Mr. Bush said Thursday. “The best thing for me to do is just talk (to Putin) about the facts.”

Mr. Bush spoke after meeting with British Prime Minister Blair.

Mr. Blair had held out hope that he could bridge an impasse between America and some other countries over setting specific targets at the meeting for reducing the greenhouse gas emissions thought to cause global warming. German Chancellor Merkel, as summit host, is pushing for binding targets.

Mr. But Bush stuck to his view that specific targets would not be the result of this week’s summit, also attended by other European leaders, as well as those from Canada, Japan and Russia.

“Nothing’s going to happen in terms of substantial reductions unless China and India participate,” the president said.

For his part, Mr. Bush sought to give some momentum for his hope to bring allies along in support of tougher action against the government of Sudan over the crisis in its Darfur region. Mr. Bush announced new American penalties against Sudan last week, but he also wants backing for a U.N. resolution to add pressure on the Sudanese government to allow a U.N. peacekeeping force.

“I’m frustrated that the international organization can’t move quickly enough,” Mr. Bush said. “I don’t know how long it’s going to take for people to hear the call to save lives. … Enough is enough on Darfur.”

The president indulged wistful thoughts about this month’s departure of Mr. Blair, for years his closest foreign ally. “It’s a nostalgic moment for me,” Mr. Bush said, the Baltic Sea shimmering behind the two men. “I’m sorry it’s come to be. But that’s what happens in life.”

In between private meetings on the sidelines, the eight leaders had a full day of summit sessions to discuss issues ranging from Africa aid to trade and Lebanon.

The gathering is being held under tight security, with Heiligendamm entirely encircled by a seven-mile, razor-wire-topped fence to keep out protesters. Some 800 demonstrators made it to the fence Wednesday, while 10,000 more reached areas in the perimeter where demonstrations have been banned.

There are many items on the disagreement list between Washington and Moscow.

Russia is unhappy about American support for independence for the breakaway Serbian province of Kosovo. It bristles at what it sees as American meddling in its affairs and its traditional sphere of influence.

Washington is getting fed up with Putin for overseeing what the U.S. perceives as an era of muzzled dissent and centralized power.

Mr. Bush this week put Russia on a par with China, calling U.S.-Russian ties “complex” and criticizing democracy as being “derailed” under Mr. Putin. The remarks carried extra sting because they were delivered publicly and in the Czech Republic. The NATO membership of the former Soviet satellite, which threw off communism in 1989, along with others, is a thorn in Russia’s side.

On the other hand, Moscow has shown more willingness of late to help the West take on Iran over its nuclear program. Washington wants to preserve this momentum.

“There’s a lot of constructive work we can do,” Mr. Bush said.

The Russians projected a similar air. They said the open hostility was part of a constructive relationship – while reaffirming disagreements with Washington’s view of Russian democracy.

But Moscow’s unrelenting objections to the proposed missile shield overshadow everything.

Russian suspicions were roused earlier this year when America chose the Czech Republic and Poland as the missile defense sites.

Mr. Peskov promised “uncomfortable consequences” if the shield is deployed “next to our borders” without more acceptable explanations from America.

But, he added: “Russia is the last country in this world who is thinking about confrontation or starting another Cold War.”