Japan’s main opposition leader criticized China over its human rights record in Tibet, a move that will likely stoke tensions amid already strained relations with Beijing.

Speaking after meeting the visiting Dalai Lama, Shinzo Abe of the Liberal Democratic Party told the Financial Times on Tuesday, “I swear I will do everything in my power to change the situation in Tibet, where human rights are being suppressed.”

“Tibet seeks freedom and democracy and we agree on those values,” he said.

China lodged a diplomatic protest with Tokyo without naming Mr. Abe, condemning Japan’s support for the Dalai Lama’s “separatist activities” and accused the Tibetan spiritual leader of “taking sides” in the territorial dispute which has damaged relations.

The spat comes at a crucial time for China as it hands over power to new leaders in a once-a-decade leadership transition that is expected to leave little room for reforms and take on similar stance on issues including the territorial row.

Self-immolations have intensified among Tibetans, underlining a growing discontent over Chinese rule. Beijing has blamed the Dalai Lama for “glorifying” such protests.