SHANGHAI, Dec 2 (Reuters) - China's foreign ministry summoned Japan's ambassador in Beijing for an "emergency meeting" on Wednesday (Dec 1) evening after former Japanese Prime Minister Shinzo Abe said neither his country nor the United States could stand by if China attacked Taiwan.

Chinese Assistant Foreign Minister Hua Chunying called Abe's remarks "erroneous" and a violation of basic norms of relations between China and Japan in the meeting with ambassador Shui Hideo, according to a statement from China's Foreign Ministry.

Abe's comments "openly challenged China's sovereignty and gave brazen support to Taiwan independence forces", it cited Hua as saying.

"China is resolutely opposed to this," it said, adding Hua had made "stern representations" to Japan.

On Wednesday, speaking at a virtual forum organised by a Taiwanese think tank, Abe said that an armed invasion of Taiwan would pose a grave danger to Japan.

Abe, who stepped down as prime minister last year, is head of the largest faction of the ruling Liberal Democratic Party and remains influential within the party.