Japan and other remaining members of the
Their trade ministers will talk on the sidelines of an Asia-Pacific Economic Cooperation (APEC) meeting in Hanoi, Vietnam, where newly appointed U.S. Trade Representative Robert Lighthizer is also due to give more detail of Washington's trade plans.
Uncertainty over those plans after Trump abandoned a trade deal he had compared to the "rape" of America has brought fears of protectionism and strengthened China's leadership credentials in Asia.
Support has built among the so-called TPP-11 for pushing ahead without the United States although trade within the smaller block is only a quarter of that between the original 12 members, according to the most recent data.
Moving ahead could help the bargaining position of the members in bilateral talks with the United States.
It could also undercut the increasing regional dominance of China, which is not part of the TPP and backs a bigger but less comprehensive free trade agreement for Asia.
"We'll be looking to see whether TPP ministers say they are definitely pushing ahead by simply by changing the articles," said Alan Bollard, executive director of the APEC Secretariat.
"Or whether they come out and say they're positive about the prospects but need more discussions," he told Reuters in Hanoi.
After initially appearing reluctant to move ahead without the United States, Japan is at the forefront of the push along with New Zealand. Japan has emphasized that it would ultimately like to bring the United States back in.
On Tuesday, Prime Minister Shinzo Abe said Japan wanted to "steer the debate toward a clear direction" in Hanoi.
The backing of some other members is less clear.
Vietnam would have been one of the biggest beneficiaries of the original TPP because of lower tariffs and more investment from the United States. Malaysia is in a similar position and an official there voiced hope of an eventual return to the TPP.
Pushing TPP forward could help Japan's position in negotiating a bilateral deal with the United States, said Nguyen Xuan Thanh of the Harvard Kennedy School. The same would apply for Vietnam, he said.
"It's part of the game," he told Reuters. "You don't want to be seen as desperate for bilateral deals."