By Doug Palmer

WASHINGTON (Reuters) - U.S. plans to negotiate a free trade pact in the Asia Pacific region pose no threat to the successful conclusion of longrunning world trade talks, the top U.S. trade official said on Tuesday.

"We actually think it might help bring Doha to a close," U.S. Trade Representative Ron Kirk said after a speech outlining the Obama administration's plan for the Transpacific Partnership, or TPP, agreement.

The United States wants to build the TPP -- which now includes only New Zealand, Chile, Singapore and Brunei Darussalam -- into a high-standard, 21st century regional free trade agreement that could eventually include all the major economies of the Asia Pacific region, he said.

The first round of talks to expand and upgrade the pact is scheduled for March between the four TPP members and the United States, Vietnam, Peru and Australia.

Kirk would not say if the eight countries had a goal of finishing an agreement by the time U.S. President Barack Obama hosts Asia Pacific leaders in Honolulu in late 2011.

But all have agreed to move quickly to complete a pact with commitments in areas from labor and the environment to emerging business sectors and more traditional trade concerns, he said.

The United States "would love to have Japan, Malaysia, Korea, a number of other economies" join the TPP, but that is up to those countries to decide, Kirk said.

KIRK SEES STRONG COMMITMENT TO DOHA

Despite the potentially huge scope of the TPP, Kirk told reporters he was convinced the new initiative would "absolutely not" undermine efforts to bring the 8-year-old Doha round of world trade talks to a close.

The United States and key Asia Pacific countries remain committed to Doha, he said.

Kirk did not elaborate on why the United States thinks the TPP talks could help bring Doha to a close.

But some trade experts argue it could put competitive pressure on WTO negotiators to resolve differences on agriculture, manufacturing, services and other trade issues that have blocked an agreement for years.

Kirk said he believed the Obama administration, working with others in the WTO, had "completely changed the negotiating paradigm around Doha" over the past six to seven months.

"We have moved from a sort of solid wall of opposition to engaging in bilateral talks to now an acceptance that's the only way to get it done," Kirk said.

Kirk joked about the challenges the Obama administration faces in the negotiations.

Other WTO members say, "'Please tell us what to do. Lead us,'" Kirk said.

"We show up and say 'OK, here's what we want' and then they all go 'how dare you? You arrogant Americans.'"

(Editing by Doina Chiacu)