Iraqi Foreign Minister Naji Sabri told reporters in the Iraqi capital, Baghdad: "It is not new... the United States has been conspiring against Iraq over the last 30 years."
US officials have confirmed a Washington Post report that Mr Bush had authorised operations to capture - or kill - Iraqi President Saddam Hussein.
Several senior US officials have publicly advocated the Iraqi leader's removal, amid speculation the United States is planning a military strike against Iraq.
Mr Sabri told a group of foreign journalists that "there is nothing new in that report, but US policy is trying to deceive world public opinion from time to time.
"We have been confronting US aggression and we have heard a lot of such threats over the last 11 years," he said.
Wider plan
Mr Bush signed a presidential order broadening the CIA's remit for overthrowing Saddam earlier this year, the Washington Post said.
It reportedly included the possible use of US special forces, such as those in Afghanistan, to try to capture the Iraqi leader, or kill him in self-defence.
The CIA has been banned by US law from assassinating political opponents abroad since the 1970s.
The order also allows for US agents to step up efforts to gain information from within the Iraqi Government, military and security services, according to the newspaper.
The Washington Post said the order was part of a wider programme by Mr Bush to bring down the Iraqi leadership, including by economic and military means.
Broad support
Both Republican and Democrat politicians in United States have welcomed the report.
The newspaper's revelations were confirmed by senior Democrat Congressman Dick Gephardt, who said he had been briefed by the White House on the plans and he thought they were a good idea.
US Defense Secretary Donald Rumsfeld said on Monday the Middle East and the rest of the world would be better off without Saddam Hussein.
Mr Rumsfeld said people did not want a country that developed weapons of mass destruction or threatened its neighbours.
He said Iraq's weapons programmes became more mature and dangerous "every day that goes by".