WASHINGTON — China’s top economic adviser arrived in Washington this week in an attempt to defuse rapidly escalating tensions with the United States as the prospect of a trade war between the world’s two largest economies looms.

But Liu He, the American-educated technocrat who is now President Xi Jinping’s top economic adviser, may face an insurmountable task. The Trump administration appears less predisposed to engage with China than perhaps any other White House in decades — a dramatic turn given the United States’ long campaign to persuade China to open its markets to American products and investment.

President Trump and his top trade advisers share a widespread view that China cannot be trusted to negotiate in good faith and believe that past administrations spent fruitless years pushing the Chinese to make minor changes to their economy that arrived too late, and were too often reversed.

News that Mr. Xi has moved to abolish term limits for himself and his vice president has only increased suspicion in recent weeks that China has no intention of shifting toward a more market-oriented economic model and plans to have a state-dominated economy.