Japan on Friday ratified the Trans-Pacific Partnership, a free-trade pact aimed at linking a dozen Pacific Rim nations, hoping it will one day take effect despite President-elect Donald Trump's pledge that the United States will withdraw from it.
The TPP, which aims to cut trade barriers in some of Asia's fastest-growing economies but does not include China, cannot take effect without the United States.
The deal, which has been five years in the making, requires ratification by at least six countries accounting for 85 per cent of the combined gross domestic product of the member nations.
Given the sheer size of the American economy, the deal cannot go ahead without US participation.
It has not been ratified by the US Senate and Trump last month promised to withdraw from it after he is inaugurated in January. Instead, he would replace it with bilaterally negotiated trade deals.
Japanese Prime Minister Shinzo Abe has said the TPP would be "meaningless without the United States".
But by ratifying the deal in parliament on Friday, Japan is signalling it hopes the accord can be resuscitated when conditions are more favourable.
Government officials said the trade pact would essentially go into deep freeze but that they would not abandon hope of reviving it in future.
Taro Kono, a senior lawmaker of Abe's ruling Liberal Democratic Party, said there was a chance that Trump would change his mind.
New Zealand Prime Minister John Key joked last month that it would be fine with him to rename the agreement Trump Pacific Partnership if that would convince the president-elect to get on board, media reported.