Prime Minister Shinzo Abe and Singaporean President Tony Tan affirmed in Tokyo on Thursday the importance of ratifying and bringing into force the Trans-Pacific Partnership trade deal to prevent a regression in the progress of free trade.

Japan, Singapore and 10 other Pacific Rim nations signed the TPP in February. It effectively requires U.S. ratification to come into force, meaning U.S. President-elect Donald Trump's pledge to withdraw from the pact as soon as he takes office in January has put its future in doubt.

"We discussed the economic and strategic importance of the TPP and agreed that it is in the interests of all TPP partners to ensure that the TPP is ratified and enters into force expeditiously," Tan told a joint press conference after the meeting.