President Bush arrived in Moscow Thursday on his first trip to Russia, one that will be marked by the signing of a landmark agreement to cut U.S. and Russian nuclear arsenals by two-thirds.

"Many generations have looked at Russia with alarm. Our generation can finally lift this shadow from Europe by embracing the friendship of a new democratic Russia," Bush said in a speech to Germany's Bundestag in Berlin delivered just an hour before his departure to Russia.

Bush and first lady Laura Bush, who disembarked from Air Force One hand in hand, had no public events scheduled for their first night in Moscow. But the president is said to be looking forward to a meeting with Russian President Vladimir Putin, who will repay the hospitality Bush showed to him in Crawford, Texas, with a visit to Putin's hometown of St. Petersburg.

The president's arrival was preceded by protests in both Moscow and St. Petersburg, including a demonstration outside the U.S. Embassy by 300 Communist protesters who waved red Soviet flags and chanted anti-Bush and anti-Putin slogans.

Speakers addressing the crowd through a bullhorn called Bush a "terrorist" and "imperialist" and criticized the new friendship between the two countries.

Friendship aside, differences continue to trouble the United States. Prior to his arrival, Bush warned Putin about his dealings with Iran, cautioning him that Russia may wind up being the target of the very weapons sold to the nation listed by the State Department this week as the biggest supporter of terrorism.

"That's going to be a problem for all of us, including Russia," Bush said.

Bush is on a four-nation, weeklong tour of Europe to shore up support for the ongoing war on terror and discuss other issues, including military agreements and trade.  Later on his trip, NATO will formalize a new agreement that makes Russia a minor partner.

Prior to his departure, Bush offered Germany's Parliament a vigorous defense of his tough stance on Iraq, though he insists he currently has no plans to take military action against the country or its despot leader Saddam Hussein.

"[Iraq is] a threat to Germany, it's a threat to America, it's a threat to civilization itself. And we've got to deal with it," Bush said.  "Like the threats of another era, this threat cannot be appeased or cannot be ignored. By being patient, relentless and resolute, we will defeat the enemies of freedom."

The president said the threat of Saddam putting chemical or biological weapons in the hands of terrorists remains high.

In Germany, politicians and protesters alike have questioned Bush's broader approach to the war on terror. For his part, German Chancellor Gerhard Schroeder deflected questions on whether he would support a U.S.-led military operation to topple Saddam, saying he didn't have to express his views since Bush told him there were no such plans under active consideration.

"There are no concrete military plans for attacks on Iraq, so no reason for me to speculate," said Schroeder, who has opposed a U.S.-led war with Iraq.

While giving his address, the president had to pause as members of a leftist party shouted and unfurled a banner reading "Mr. Bush and Mr. Schroeder, stop your wars."

Bundestag officials tore the banner from their hands and ejected them from the chamber.

Though the party is hardly representative of all Germans, it did represent the concerns of thousands of protesters, who have spent the last three days demonstrating in the streets of Berlin against any expansion of the war into Iraq.

Some 20,000 took to the streets as Bush arrived in Berlin late Wednesday. And while the protests were mostly peaceful, violence broke out among groups of hooded youths and pro-Palestinian demonstrators.

An American flag was burned, and demonstrators pelted police in riot gear with bottles and stones. Police said 58 people were arrested.

The demonstrators were kept far away from Bush and his entourage by multiple barricades and some 10,000 police officers, the largest police operation in Berlin since World War II.

Bush, who knows there is widespread discomfort over his hard line toward Saddam, addressed the issue head on in his speech.

"Wishful thinking might bring comfort, but not security. Call this a 'strategic challenge', call it, as I do, 'axis of evil', call it by any name you choose, but let us speak the truth," he said. 

Bush appealed for Germany's help in exerting diplomatic pressure on Iraq to keep Saddam from developing destructive weapons — a threat he said is likely.

He said he advocates action against Iraq because "I don't want to be in a position where we look back and they say, 'Why didn't they lead? Where were they when it came to our basic freedom?"'

In a nod to German skepticism of his hard line on Iraq, Bush told a press gathering prior to his speech that Germany has "shouldered a significant burden" in the overall fight against terrorism, "and we're very grateful for that."

Fox News' Jim Angle and Wendell Goler and the Associated Press contributed to this report.