Japanese Prime Minister Shinzo Abe visited a controversial shrine to World War II dead, including 14 convicted war criminals, ignoring U.S. advice against gestures bound to strain already tense relations with neighbors China and South Korea.

Abe told Japanese news media the visit was intended “to report the progress of the first year of my administration and convey my resolve to build an era in which the people will never again suffer the ravages of war.”

But the visit drew immediate rebuke from Beijing and Seoul, where officials fear Japan’s nationalist leader is steering his country back to the militarism of the war years and those preceding them.

China’s Foreign Ministry summoned the Japanese ambassador in Beijing to formally protest Abe’s visit to the Yasukuni shrine in Tokyo, the first by a sitting prime minister since 2006.

The visit “has created major new political obstacles for already strained Sino-Japanese relations, and China won’t ever tolerate it,” Foreign Minister Wang Yi said in a statement. He warned that if Japan continues its provocative course of action, “China will surely keep it company to the end.”

Abe’s visit and the first anniversary of his second term as prime minister also coincided with events in China commemorating the 120th birthday of late leader Mao Zedong.

Relations between the two Asian economic giants have been increasingly tense since Japan’s purchase last year of uninhabited islands in the East China Sea. China last month retaliated by pronouncing an air defense identification zone over the disputed islands and demanding that any aircraft overflying the region inform Beijing authorities of their flight plans. Both Japan and China have scrambled warplanes to demonstrate control of the air and maritime spaces, provoking fear of an accident or escalation.The new Chinese air exclusion zone also overlaps air space claimed by South Korea, which has its own dispute with Japan over islands in the strategic and mineral-rich East Asian maritime corridor.

South Korean Culture Minister Yoo Jin Ryong deplored Abe’s visit to the shrine, which he said “glorifies Japan’s history of militaristic aggression and colonial rule.”

During a visit to Japan in October, U.S. Secretary of State John F. Kerry and Defense Secretary Chuck Hagel advised Abe to avoid ratcheting up regional tension by visiting the Yasukuni shrine, the Japan Times said in its article on Thursday’s visit.