Prime Minister Shinzo Abe expressed eagerness Friday to achieve an early ratification of the Trans-Pacific Partnership free trade pact, with fears growing the agreement may not take effect anytime soon despite the signing in February.

"We will make efforts to get the endorsement of related bills (to ratify TPP) in the extraordinary Diet session" scheduled to be convened next Monday, Abe said at a press conference in the Cuban capital, Havana, during the first visit to the communist country by a Japanese leader.

His remarks came after U.S. Democratic Party presidential nominee Hillary Clinton reiterated her opposition to the U.S.-led trade agreement during a meeting with Abe earlier this week on the sidelines of the U.N. General Assembly in New York.

Abe emphasized at the press conference that the 12-nation free trade pact is expected to bolster the possibility of growth in fields such as agriculture and small and midsize businesses in Japan.

But the agreement may not be implemented anytime soon if U.S. President Barack Obama fails to persuade Congress to approve it, as Republican presidential nominee Donald Trump also opposes the TPP deal.

Covering about 40 percent of the global economy, the TPP groups Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore, the United States and Vietnam.

The trade agreement will enter into force 60 days after all 12 countries ratify it. However, if all 12 nations have not ratified it after two years, it will take effect 60 days after at least six countries, accounting for 85 percent of the combined gross domestic product of the 12 signatories, do so.