Moscow ? The White House’s assertion that the war in Iraq is part of a global struggle against terror won support Friday from one of the leading foreign critics of the war, Russian President Vladimir V. Putin.

Putin said Russian security agencies repeatedly had warned the White House after Sept. 11, 2001, that Saddam Hussein was planning “terrorist attacks” against targets both outside and inside the United States.

“This information was passed through channels to American colleagues,” he told reporters in Astrana, the capital of the Central Asian state of Kazakhstan. “George Bush had a chance to personally thank a chief of one of the Russian secret services for the information that he considered very important.”

The disclosure appears to help the White House justify invading Iraq, by depicting Saddam as an imminent threat. And it plunges the Russian president into America’s presidential campaign, because the Democrats have accused President Bush of launching the war with little justification.

“It appears Mr. Putin is trying to help Mr. Bush win his second election, that Moscow is becoming a player in the American political scene,” said Lilia Shevtsova, a political scientist at the Moscow Carnegie Center, in an interview.

In the weeks leading up to the invasion last year, Putin challenged the United States’ rationale for invasion. Later, he noted Washington, D.C.’s failure to find weapons of mass destruction. And he repeatedly has said Russia would never send troops to Iraq.

Washington’s response to Russia’s refusal to support the war was muted compared with the response of other critics, including France and Germany.