President Bush is in Prague at the start of a six-nation tour of Europe, where tensions with Russia have been heating up over the US plan to deploy a missile defense system in the Czech Republic and Poland.
Missile defense tops the agenda for the president when he meets with Czech leaders, who have agreed to host part of the missile defense system Washington wants to deploy in Eastern Europe.
The deployment plan has drawn a strong response from Russian President Vladimir Putin who says it is the start of a new arms race in Europe.
President Putin told reporters in Moscow that President Bush's missile plan is upsetting the world's strategic balance, and Russia will respond by targeting Russian missiles at European cities. According to a transcript released by the Kremlin, Mr. Putin said those targets could be hit with ballistic missiles or cruise missiles or what he called a "completely new system."
President Putin said he believes the US plan could be an effort to undermine Russia's relations with Europe.
President Bush meets with President Putin during this trip on the sidelines of the G-8 summit in Germany.
Mr. Bush's National Security Adviser Steve Hadley says the president will again stress that the missile defense system is no threat to Russia.
"The systems we would deploy do not have capability of any significant character against Russian ICBMs destined for the - that are aimed at the United States. Just doesn't have any capability. It's a very limited capability about other states, like Iran, who are developing ballistic missiles and potentially the weapons of mass destruction that those missiles could deliver. So it's all about Iran."
Iran's top security official says that is a joke. Supreme National Security Council chief Ali Larijani told Iran's state-run news agency that the country does not have missiles capable of reaching Europe.
During his talks in Prague Tuesday, President Bush meets with the Czech president and prime minister to thank them for their support in Afghanistan and Iraq. He will also meet with dissidents and address a pro-democracy forum at the Czernin Palace. Later in the week the president will be in Germany for a meeting of leaders from the leading industrial countries.