WASHINGTON: A senior Pentagon official says Iraqi strongman Saddam Hussein has stepped up training exercises for his troops and may be planning a new invasion of Kuwait. But the White House is downplaying the news as speculation. "I am not aware of anything that would suggest any offensive designs" on Saddam's part, said spokesman Mike McCurry. State Department spokesman Nicholas Burns said the U.S. is closely watching Iraqi military movements: "We have no evidence that Iraq is staging new moves to threaten its neighbors." Speaking on the condition of anonymity, the Pentagon official told reporters that that Iraqi planes have been flying heavy sorties -- 100 in one night alone -- and that Saddam "comes in every morning and makes a decision" on whether his army should move toward Kuwait. While the official described Saddam as irrational, he cautioned that an invasion is not imminent. The high number of recent troop movements might also have a less troubling explanation: to train new commanders put in place after a wide-ranging purge. A leading Iraqi opposition leader said last week that Saddam's security forces rounded up about 600 people, among them over 20 military officers, in retaliation for an assassination attempt on his oldest son Odai. While the U.S. has no ground troops in the Persian Gulf to counter a sudden Iraqi move, the Army plans to hold exercises there next month and is working toward a "near-continuous presence."