Relations between the two countries have warmed since the Xi-Trump telephone call, laying the ground for their G20 meeting.
In a further sign of improving ties, Chinese Politburo member Yang Jiechi and Defence Minister Wei Fenghe are set to hold a security and diplomatic dialogue with U.S. officials in Washington on Friday.
Meeting U.S. national security adviser John Bolton in Washington ahead of those talks, Yang said on Wednesday that the two sides should "properly manage differences and carefully prepare to ensure positive results in the Argentina meeting", China's Foreign Ministry said in a statement.
"China is committed to working with the U.S. to achieve a no-confrontational, conflict-free, mutually respectful co-operation in which both sides win," added Yang, who heads the ruling Communist Party's foreign affairs commission and outranks Wang.
However, speaking in Singapore at a forum on Wednesday, former U.S. Treasury Secretary Henry Paulson said there was a risk of an economic "Iron Curtain" falling between China and the United States unless China carried out reforms and that some people in the United States would like to "divorce" China.
Beijing can help avoid this happening by ending practices like forced technology transfers, and providing better protection for intellectual property, and by also genuinely allowing market forces to drive key decisions.
"If China doesn't move quickly, I suspect the calls for divorce will intensify," Paulson said.