"It would be surprising to me if we did not have more fits and starts, more stop-and-go in these trade talks given the wide range of issues at stake and given the complexity," said Charles Dallara, Partners Group chairman of the Americas on Wednesday.
"I see late May, June more as kind of the realistic time frame than I see anything in April," said Dallara, a former managing director and CEO at the Institute of International Finance.
"If we move into that time frame, I think some understandings will be reached and I think that will be a critical step forward," he told CNBC at the Boao Forum for Asia in the Hainan province of China.
The world's top two economies have been embroiled in a trade dispute that spooked world equity markets last year and dented the global growth outlook. Trade talks between the two countries broke down in mid-February, with the U.S. warning "very difficult issues" were still unresolved.
Their next meeting on Thursday and Friday will bring U.S. top trade negotiator Robert Lighthizer and Treasury Secretary Steven Mnuchin to Beijing. Chinese officials expected to continue those talks in Washington in April.
Dallara said the talks would be "the first step in a new phase of the economic relationship between China and the U.S.," and to a lesser extent, between Beijing and the rest of the world.
"I think that relationship inevitably was going to be rebalanced and I think it's beginning to happen now — but it will be a long evolution; it won't happen overnight," he added.
— CNBC's Sam Meredith contributed to this report.