SEOUL (Reuters) - The Bush administration can find support in Congress for major U.S. policy changes toward North Korea if a deal is struck on dismantling Pyongyang"s nuclear weapons program, a U.S. congressman said on Sunday.

Jim Leach, a Republican who heads the House Subcommittee on East Asian and Pacific Affairs, also said upon returning from a trip to North Korea that Pyongyang seemed committed to returning to six-party nuclear talks scheduled for next week in Beijing.

Leach said Congress would have to approve new policies toward North Korea and it was in Pyongyang"s interest to strike a deal now because of the special relations the Republican-controlled Congress has with President George W. Bush, a Republican.

Leach did not mention any specific measures, but Congressional approval would be necessary for certain demands from North Korea such as establishing diplomatic ties, striking a peace treaty to formally end the 1950-53 Korean War and dispatching U.S. economic aid.

"This administration"s tough policies had certain advantages in dealing with this Congress on the huge changes in law that would be necessary if there were a change of policies for North Korea," Leach told a press conference.

Leach traveled to North Korea for four days last week with Tom Lantos, the ranking Democrat on the House International Relations Committee.

Talks between the two Koreas, China, Japan, Russia and the United States had been scheduled to resume in the week of August 29 but North Korea blamed joint South Korea-U.S. military drills and the U.S. appointment of a monitor on its human rights as the reasons for its decision to postpone its return.

Leach said that now was not the time for foot dragging.

"We stressed that delay was not in anybody"s interest, either procedurally or substantively," Leach said.

Leach said Pyongyang officials expressed "their strong commitment" to the U.S. congressman to return to the talks in the week of September 12.

During their visit, Lantos and Leach held talks with Vice Foreign Minister Kim, Foreign Minister Paek Nam-sun, Vice President of the Supreme People"s Assembly Kim Song-dae and General Li Chan-bok of the Korean People"s Army.

Leach also said North Korea wanted to press for a right to a peaceful nuclear program, which was a key stumbling block in the previous session of nuclear talks that took place for 13 days in late July and early August.

Leach said Congress had concerns about allowing North Korea to have a peaceful nuclear program after Pyongyang left the nuclear Non-Proliferation Treaty in January 2003, expelled International Atomic Energy Agency inspectors from its country in December 2002, and was seen by Washington as violating a 1994 agreement to freeze its nuclear programs.

"These issues of trust are very large and will take some time to unfold," Leach said.