The US and China need to come together to give global climate negotiations a “big push,” according to Singapore’s Minister for Sustainability and the Environment Grace Fu.

The world’s biggest greenhouse gas emitters are making progress on their own net-zero targets but need to continue discussions with each other, especially at the G20 summit in India in September, Fu said at Bloomberg’s Sustainable Business Summit on Wednesday.

US Climate Envoy John Kerry’s trip to China last week ended without any grand bargain, although the two sides did promise to keep talking. The negotiations were complicated by internal political dynamics in the two countries, which are sparring over trade controls, human rights and other issues.

The US is also attempting to challenge China’s dominance in clean energy industries like solar panels and electric vehicle batteries.

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Despite the tensions, it’s positive Kerry met with his Chinese counterpart, Xie Zhenhua, Fu said. “It is a good sign. They are talking and they were not talking before,” she said. “Is it going to be easy? Not at all. But we are hopeful.”

--With assistance from Annie Lee.