A senior Chinese political leader said Tuesday the country's once frosty relations with Japan have started thawing following a series of recent exchanges.

"Sino-Japanese relations have taken the welcoming initial step toward improving," Zhang Dejiang, ranked third in China's Communist Party, told a cross-party group of Japanese lawmakers at the outset of a meeting in Beijing.

The group's three-day visit to Beijing that started Monday came after Prime Minister Shinzo Abe and President Xi Jinping met April 22 for the second time in five months and agreed to advance a range of exchanges to enhance mutual trust, despite outstanding disagreements over territory and wartime history.