Wamp, a Chattanooga Republican, said the meetings Monday and Tuesday will be with diplomats of European countries and several Middle Eastern countries and U.S. Ambassador John Bolton. He will attend with Rep. Adam Putnam, R-Fla., chairman of the Republican Policy Committee.

Wamp, who also represents the Oak Ridge area, was chosen because of his work on nuclear nonproliferation issues and his membership on the homeland security appropriations subcommittee.

"I am very concerned that this threat in Iran is one of the greatest threats that our country has faced in a long time," Wamp said in an interview. He said he hopes the trip will yield a bigger coalition of countries willing to pressure Iran to stop any nuclear weapons development.

If the United States cannot get U.N. Security Council support to deal with Iran, Wamp said, it would be time, in his opinion, for the U.S. to begin withdrawing from the U.N. and work with a body of allies that could extend beyond NATO members. Wamp said he talked about the matter in a meeting with President Bush about three weeks ago, and also has had meetings with the secretaries of state and defense.

The House may vote on a resolution next month to make a stronger stand calling for U.N. action, Wamp said.