Malaysian Prime Minister Najib Razak, during talks Thursday with Prime Minister Shinzo Abe, showed his “understanding” of Japan’s deep concern over China’s newly declared air defense identification zone in the East China Sea, a Japanese official who attended the meeting said.

Najib and Abe met ahead of special sessions of the Association of Southeast Asian Nations that will start Saturday in Tokyo.

Abe plans to have bilateral meetings with the leaders of all 10 ASEAN countries from Thursday through Sunday.

He is expected to try to garner support to keep China in check by emphasizing Beijing may set a similar ADIZ in the South China Sea, which is partly surrounded by ASEAN countries.

During the 45-minute meeting with Najib in the prime minister’s office, Abe claimed China is unilaterally trying to change the status quo in the East and South China Seas, and Tokyo will not accept such a move, according to the official who briefed reporters.

Beijing may set a similar air defense zone over other areas, which could have a dramatic impact on ASEAN, Abe reportedly told Najib.

In response, Najib acknowledged Abe’s concerns and said ASEAN should deal with diplomatic rows over territories in the South China Sea through a “multilateral” approach, not bilateral ones, according to the official.

Japan hopes to cooperate with Malaysia to secure freedom of navigation and flights over the high seas, Abe was quoted as saying.

Najib told Abe that ASEAN “will work together as one” to seek peaceful solutions over disputes in the South China Sea, according to the Japanese official.

Among the 10 ASEAN countries, Laos and Cambodia have maintained relatively close relations with China, while Beijing’s ties with Vietnam and the Philippines are strained over territorial rows in the South China Sea.

How those leaders comment on their relations with China will be a focus of public attention in the Tokyo gathering.

In addition to the ASEAN session Saturday, Abe plans to have one-on-one meetings with the leaders of Brunei, the Philippines, Indonesia and Singapore on Friday, and the leaders of Laos, Myanmar, Vietnam, Thailand and Cambodia on Sunday.

Najib praised Japanese companies’ technologies, and urged Japanese firms to place bids for infrastructure Malaysian projects.