The leaders of 12 countries involved in the recently sealed Trans-Pacific Partnership free trade initiative will meet later this month in the Philippines to ensure early implementation of the pact, a government source said Wednesday.

The meeting will be held on the sidelines of a two-day summit of the Asia-Pacific Economic Cooperation forum from Nov. 18 in Manila, according to the source.

Japan, the United States and 10 other countries reached a broad agreement a month ago on the Pacific Rim free trade deal that covers 40 percent of the global economy and sets rules on international trade, investment and the handling of intellectual property.

Some other countries such as South Korea are also interested in joining the Pacific trade initiative.

The 12 participating nations will need to finalize the text of the treaty before the accord can be readied for formal approval in the respective jurisdictions, leading to eventual ratification.

The leaders of the 12 nations, all members of the APEC forum, will welcome the agreement in a joint statement to be issued after their meeting, which will be the first since November last year.

Some countries are facing a major challenge to bring the agreement into force smoothly.

U.S. lawmakers, for example, are seen as reluctant to discuss the accord aggressively, as the matter could be a drag on domestic employment ahead of next year's presidential election.

The TPP nations initially sought to sign the deal at the meeting in Manila. But the later-than-expected broad agreement made that difficult.

TPP members also include Australia, Brunei, Canada, Chile, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam.