US President George W. Bush said he hoped to convince Russian President Vladimir Putin on Thursday that their dispute over a US missile defense system is not an issue either side should "be hyperventilating about." Bush and Putin hold talks Thursday afternoon on the sidelines of the Group of Eight summit - their first meeting since a clash over US plans for a missile defense system in Eastern Europe flared into Cold War-style rhetoric. Bush said he would try to ease Russia's concerns about the shield and convince him the intention is to block missiles from Iran - not Russia, which has a huge arsenal of nuclear rockets that the system would not be capable of deterring. "A missile defense system cannot stop multilaunch regimes. ... The fact is that you can't stop two, three, four, five missiles," Bush said after a meeting with British Prime Minister Tony Blair. "Russia is not a threat," Bush said. "They're not a military threat. They're not something that we ought to be hyperventilating about. What we ought to be doing is figuring out ways to work together." But Moscow has dismissed that as an "insufficient" explanation. Putin warned earlier this week that a new shield could require Russia to retarget missiles toward Europe or take other buildup measures, and a Kremlin spokesman promised "uncomfortable consequences" if the shield is deployed. But, spokesman Dmitry Peskov added, "Russia is the last country in this world who is thinking about confrontation or starting another Cold War." There are other items on the US-Russia disagreement list, notably Russia's unhappiness with US support for independence for the breakaway Serbian province of Kosovo. Russia bristles at what it sees as US meddling in its traditional sphere of influence. Bush this week put Russia on a par with China, calling US-Russian ties "complex" and criticizing democracy as having being "derailed" under 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. However, Moscow has shown more willingness of late to help the West take on Iran over its nuclear program, and Russian officials said the open hostility was part of a constructive relationship. "This summit isn't about disagreements between Russia and the rest of the G-8 members," Peskov said late Wednesday, adding that he hoped for "an open and sincere exchange of views" between Bush and Putin.