A bipartisan group of Diet members focusing on relations with the U.S. has resumed its activities for the first time in four years, and ahead of the meeting of Prime Minister Shinzo Abe and President Barack Obama later this week.

The group had been idled since 2009 when its former head and former Foreign Minister Taro Nakayama lost an election. It resumed operating Monday with Hirofumi Nakasone, head of the Liberal Democratic Party's Upper House caucus, taking the helm.

The group's first meeting was attended by about 50 lawmakers, including from the LDP, New Komeito and the Democratic Party of Japan.