By Linda Sieg
TOKYO (Reuters) - Japan needs details of China's plans for Sept 3. events to mark the anniversary of World War Two before it decides if Prime Minister Shinzo Abe will visit Beijing then for a summit with Chinese President Xi Jinping, a Japanese government source said.
China will hold a military parade on Sept. 3 to top off the commemoration of what its state media call the "Victory of the Chinese people's war against Japanese aggression".
Sino-Japanese ties, embittered by a territorial row, the legacy of Japan's wartime occupation of parts of China and regional rivalry, have thawed slightly since Abe and Xi met at multilateral gatherings in April and last November.
"Both sides have the sense they want to have a leaders' meeting to advance Sino-Japanese relations," the source told Reuters on Thursday.
"This would be the first real Japan-China summit. We would like to do this, but there are aspects of the ceremony which are not negotiable," he added, without elaborating.
China has invited Abe to attend the event, but diplomatic experts said Tokyo wants to make sure the commemoration is not embarrassingly anti-Japanese before accepting.
The source stressed no decision had been made about any visit, but said Abe was likely to skip the parade if he went.
China's foreign ministry on Wednesday denied a report by the Mainichi newspaper that Abe would visit China on Sept. 3 but not attend the parade, saying it had "never heard of" such a visit.
China's reaction to Abe's Aug. 14 statement marking the end of World War Two had been "basically restrained", the source said.
In his remarks, Abe upheld previous Japanese governments' apologies over the war, but made no new apology of his own.
Economic matters would be a key theme of any summit, the source said, but a row over disputed islands in the East China Sea, and China's growing assertiveness in the South China Sea, would also figure.
"There are many economic topics to discuss," he said. "The mutual impact is huge."
The slowing growth of Japan's exports to China, its biggest trading partner, was worrisome, the source added.
Exports to China rose 4.2 percent in July on the year, from June's figure of 5.9 percent. Japan's economy shrank an annualized 1.6 percent in the April-June quarter.
"The impact of the slowdown in China's economy has clearly emerged," he said.
But any decision on measures to bolster growth would come only after looking at data for the July to September quarter, the government source added.
(Reporting by Linda Sieg; Editing by Clarence Fernandez)