Russian President Vladimir Putin says that after the 9/11 attacks Moscow warned Washington that Saddam Hussein was planning attacks on the US.
Putin was a vocal opponent of the US-led war in Iraq
He said Russia's secret service had information on more than one occasion that Iraq was preparing acts of terror in the US and its facilities worldwide.
Mr Putin said he had no information the Iraqi ex-leader was behind any attacks.
It came a day after US President George W Bush insisted there had been links between Saddam Hussein and al-Qaeda.
He disputed the preliminary findings of a US commission investigating the 9/11 attacks on Washington and New York that found no "credible evidence" of a relationship between the two.
Speaking on a visit to Kazakhstan, Mr Putin said Russia had warned the US on several occasions that Iraq was planning "terrorist attacks" on its soil.
"After the events of 11 September 2001, and before the start of the military operation in Iraq, Russian special services several times received such information and passed it on to their American colleagues," he told reporters.
He said the information received by Russian intelligence suggested Iraq was planning attacks in the United States, "and beyond its borders on American military and civilian targets".
But he said it did not change Russia's opposition to the war in Iraq.
"Despite that information... Russia's position on Iraq remains unchanged," he said.
He added: "It is one thing to have information that (Saddam) Hussein's regime was preparing acts of terrorism - we did have this information and we handed it over.
"But we did not have information that they were involved in any terrorist acts whatsoever and, after all, these are two different things."
The BBC's Steve Rosenberg in Moscow says Mr Putin's remarks are a surprise - considering his vocal opposition to the US-led war in Iraq.
But they will come as a relief to President Bush, following the bi-partisan commission's report saying it had found no credible evidence of a collaboration between al-Qaeda and Saddam Hussein.