China's foreign minister has said that the atrocities committed by Japan during World War II deserve "even more attention" than the atomic bombing of Hiroshima.

Ahead of U.S. President Barack Obama's landmark visit Friday to the bombed city, the official Xinhua News Agency quoted Chinese Foreign Minister Wang Yi as telling reporters that "while Hiroshima is worthy of attention, Nanjing should not be forgotten and deserves even more attention."

Nanjing is a reference to the city formerly known as Nanking, which was the Kuomintang government's capital and site of the 1937 Nanking Massacre — often referred to as the "Rape of Nanking." Beijing says 300,000 people were slaughtered after the city fell to soldiers in 1937 following Japan's invasion, although those figures are disputed.

Wang, who was responding to a question about foreign leaders' visits to Hiroshima, said, "The (Hiroshima) victims deserve sympathy ... but the perpetrators could never shake off their responsibility."

China has accused Japan of failing to fully come to terms with its wartime aggression and has questioned the sincerity of its apology for its rampage through Asia during the war. Beijing rarely misses a chance to remind the world of its suffering at the hands of Japan during the conflict, which it calls The War of Resistance against Japanese Aggression.

In an editorial Friday, Xinhua criticized the nature of Obama's Hiroshima visit, claiming it was designed to bolster the U.S. "pivot" to Asia while also giving Prime Minister Shinzo Abe a political win ahead of a key election this summer.

The visit "should not be used as an occasion to whitewash Japan's atrocities in WWII," Xinhua said.