WASHINGTON -- Rep. Mike Simpson of Idaho says U.S. troops in Iraq have helped lower the level of violence and improved the country's political outlook.

The Republican said Thursday that "the surge is clearly working," adding that U.S. troops and the Iraqi military have made great strides in fighting insurgents and improving security since he last visited Iraq in 2004.

Simpson traveled to Iraq and Kuwait last weekend as part of a six-member delegation led by House Appropriations Committee Chairman David Obey, D-Wisc., and Rep. John Murtha, D-Pa., chairman of the Defense Appropriations subcommittee.

The group met with U.S. Ambassador Ryan Crocker and Gen. David Petraeus, commander of U.S. forces in Iraq, as well as members of the Iraqi government.