Sen. Elizabeth Warren, D-Mass. Bill Clark | CQ Roll Call | Getty Images

China may be better off agreeing to a deal with U.S. President Donald Trump while he's in office, an analyst told CNBC on Tuesday. That's because things could get tougher if Elizabeth Warren, a potential Democratic rival, wins next year's presidential election. Warren, a U.S. senator seeking the Democratic Party's presidential nomination, could bring up more difficult issues when negotiating with China, said Wayne Kaufman, chief market analyst at Phoenix Financial Services. That would add to the many sticking points, which currently include the lack of intellectual property rights protection, making it harder for both sides to seal a deal. An NBC News/Wall Street Journal poll last month placed Warren just behind former Vice President Joe Biden as the favored candidate to win the Democratic presidential nomination. "The Chinese, they would like to wait out President Trump ... they may be miscalculating because if they get a President Elizabeth Warren, she's probably going to be even tougher than Trump," Kaufman told CNBC's "Street Signs Asia." "Warren will go after them in a worse way because of climate change. She's a big, big climate change person. China is the biggest polluter in the world so the Chinese may want to deal with Mr. Trump who I think wants to have some deal done by first quarter," he added.

The U.S.-China trade war escalated in recent months after both sides raised tariffs on each other's goods. The two countries are set to resume high-level trade talks this week, but media reports said Chinese officials have grown hesitant to pursue a broad trade deal that include reforms to Beijing industrial policy and subsidies. Such developments have led many analysts to lower their expectations that both sides would reach a trade deal before the 2020 U.S. presidential election. Still, Kaufman is not the only one who suggested Trump may turn out to be China's best bet. Clete Willems, a former deputy director of the National Economic Council in the Trump administration, told CNBC last week that "being tough on China is about the only thing" with bipartisan support in Washington. "If you're in a scenario where you have someone like Elizabeth Warren as president, I think she's going to be almost as tough as the president on China," Willems, now a partner at law firm Akin Gump, said at that time. "And she may even throw in other issues that he doesn't focus on like human rights, environment and labor, and use that to be tough on China."

Prolonged US-China trade war

The U.S.-China trade war has hurt business sentiment, rocked financial markets and dampened the prospects of global economic growth. Continued friction between the two economic powers could change the structure of the global economy in the longer term, said James Sullivan, head of Asia ex-Japan equity research at J.P. Morgan.