The idea of Japan joining the China-led Asian Infrastructure Investment Bank is finding renewed enthusiasm within the administration of Prime Minister Shinzo Abe, sources have said.

The idea has advocates within the Prime Minister's Office and the trade ministry, and is backed by Toshihiro Nikai, the pro-China secretary-general of Abe's Liberal Democratic Party.

But a senior official at the Foreign Ministry dismissed the idea, saying "we're not considering participating."