The long-awaited free trade agreement signed Sunday between 15 Asia-Pacific countries after eight years of talks reflect their determination to strengthen economic unity and promote free trade, regardless of political differences, as questions loom over how U.S. President-elect Joe Biden will engage with the region.

Japan hopes the Regional Comprehensive Economic Partnership, which includes China and South Korea and represents 30% of the world's trade and population, will encourage the United States to return to a multilateral trade framework.

"Regarding RCEP, it may create discussions in the United States, such as 'is it okay that we are sitting out when a free trade network is created in the Indo-Pacific?'" a senior Japanese diplomat said.