Washington ? President Bush said Tuesday he will ask the United Nations “to deal with the problem” of Iraq and dispatched top members of his national security team to Capitol Hill to talk to skeptical lawmakers.

Bush tied his goal of toppling Iraqi President Saddam Hussein to the war on terror he began after the Sept. 11 attacks a year ago.

“I’m deeply concerned about a leader who has ignored the United Nations for all these years, refused to conform to resolution after resolution after resolution, who has weapons of mass destruction,” Bush said during a visit to the Afghan Embassy. “And the battlefield has now shifted to America; so there’s a different dynamic than we’ve ever faced before.”

The president does not plan to offer new information about an Iraqi threat or recommend any specific actions in his Thursday speech, a senior White House official said on condition of anonymity. Lawmakers said George Tenet, the director of central intelligence, and national security adviser Condoleezza Rice likewise gave no new information in congressional briefings Tuesday.

U.S. allies and members of Congress have urged Bush to give them more evidence that Saddam’s nuclear, biological and chemical weapons programs pose a direct threat.

In his U.N. speech Thursday, the administration official said, Bush plans to respond with a challenge of his own: “What more do we need to know?”

Outside experts and U.S. officials say Iraq probably has stocks of chemical and biological weapons and could make a nuclear bomb if it could obtain enough nuclear material. Iraq denies having weapons of mass destruction.

“This is not something where you can wait until you have clear evidence,” Deputy Defense Secretary Paul Wolfowitz said in a Tuesday interview with AP Broadcast.

“In fact, one of the fundamental points that Sept. 11 should have brought home to us is that you may not have a clear case after the fact, because the nature of terrorism is that it operates in the shadows, and it could be a way for a country that wants to do us harm to do it in a semi-anonymous way.”