(Rewrites with comments from more senators, Commerce secretary)
WASHINGTON, May 16 (Reuters) - The Trump administration's top trade officials hope to keep the North American Free Trade Agreement as a trilateral deal in negotiations with Canada and Mexico to revamp the 23-year-old pact, senators said on Tuesday.
Several members of the Senate Finance Committee said Commerce Secretary Wilbur Ross and new U.S. Trade Representative Robert Lighthizer told them in a closed door meeting that they would prefer the current three-nation format but left open the possibility of parallel bilateral agreements with Canada and Mexico.
"Their preference is trilateral," Democratic Senator Debbie Stabenow told reporters after the meeting.
Republican Senator Charles Grassley of Iowa said from the meeting it sounded to him as if a trilateral deal was more likely "unless there's problems" with that approach.
"If trilaterally you aren't getting anyplace, I suppose then you do it bilaterally," Grassley said.
Ross, who has floated the idea of doing two bilateral trade deals with Canada and Mexico, declined to confirm the administration's preference for a trilateral approach.
"Right now it is a trilateral deal and we shall see what comes in the future but the important thing is to get to the substance," Ross told reporters after leaving the meeting, adding that talks would be "long and complicated."
The meeting was one of several on Capitol Hill this week involving Lighthizer, who was sworn in as U.S. trade representative on Monday, that are required for the Trump administration to trigger the start of the NAFTA negotiating process with a 90-day consultation period.
Farm state senators said they also warned Ross and Lighthizer not to take actions that would damage agricultural exports to Canada and Mexico.
"We made it pretty clear that's a priority, that we don't want to see ag hurt," said Senator John Thune, a South Dakota Republican. "NAFTA by and large has been good for agriculture, and we're seeing some disruptions in the ag marketplace today because of uncertainty about where this is headed."
Senator Ron Wyden of Oregon, the Finance Committee's top Democrat, said Ross and Lighthizer assured him they would push to drop NAFTA's dispute-resolution mechanism. Trump has complained that the mechanism is biased against the United States. (Reporting by Dave Lawder; Writing by Eric Walsh; Editing by Leslie Adler and Bill Trott)