The US Trade Representative's office said China pledged to purchase "a substantial amount" of agricultural, energy and manufactured goods and services from the United States, after talks ended in Beijing but gave no specific details.
"Not that we've got a concrete resolution, but the headlines seem to indicate the talks went well and perhaps the two sides are putting together a draft statement, which would be positive," said Mona Mahajan, US investment strategist, Allianz Global Investors in New York.
The S&P technology index rose 1.61 percent, boosted by Apple Inc, Microsoft Corp and chipmakers. Apple rose 2.1 percent, springing back from a slump last week after the company cut its holiday quarter sales estimate. The gains came despite a Nikkei report on planned production cut for new iPhone models for the January-March quarter and a cut in earnings estimate by supplier Skyworks Solutions Inc.
Chip stocks gained 2.80 percent, a reversal from Tuesday's drop triggered by Samsung's profit warning, led by Micron Technology's 6.5 percent after Bernstein upgraded the stock to "outperform".
Shares of Boeing Co, which has a large exposure to China, were up 1.5 percent, with the S&P industrial index gaining 1.1 percent. At 1:01 p.m. ET, the Dow Jones Industrial Average was up 176.18 points, or 0.74 percent, at 23,963.63. The S&P 500 was up 19.11 points, or 0.74 percent, at 2,593.52 and the Nasdaq Composite was up 76.85 points, or 1.11 percent, at 6,973.84. Financial stocks were up 0.81 percent ahead of the release of Fed's minutes from its December meeting.