President Trump said on Dec. 31 that the signing would take place on Jan. 15. The two sides had been expected to come together as early as the first week of January.
"I will be signing our very large and comprehensive Phase One Trade Deal with China on January 15," the president wrote on Twitter last month. "The ceremony will take place at the White House. High level representatives of China will be present. At a later date I will be going to Beijing where talks will begin on Phase Two!"
The delegation will return to China on Jan. 16, according to the South China Morning Post. Vice Premier Liu He is expected to lead the delegation.
The U.S.-Mexico-Canada Agreement, another big trade deal, may pass the Senate days before the "phase one" signing.
"On Jan. 15, just a few days later, we're going to sign the 'phase one' China deal, so you could have, within a space of a week, leading off 2020, two of the biggest and best trade deals ever signed in American history," White House trade adviser Peter Navarro told Fox's Maria Bartiromo on Sunday.
The partial trade deal, which was agreed to on Dec. 12, calls for Beijing to purchase $200 billion worth of U.S. products over the next two years, in addition to protecting against intellectual property theft and technology transfer.
In return, the U.S. has agreed to reduce its tariffs on Chinese goods, but will still levy duties against $380 billion of those products.
FOX Business' inquiry to the office of the U.S. Trade Representative was not immediately returned.
FOX Business' Jonathan Garber contributed to this report.