The acquisition has been caught up in the U.S.-China trade war and is believed to have been stalled until there is some breakthrough in the broader bilateral talks. The deal has got a nod from eight of the nine required global regulators, with China the only one dragging its feet.

Qualcomm is likely to meet Chinese regulators before U.S. Commerce Secretary Wilbur Ross arrives in China on Saturday, the sources briefed on Qualcomm’s discussions said.

A Qualcomm team and officials from the State Administration for Market Regulation (SAMR) met in Beijing last week and had “productive” talks, the sources said.

The San Diego-based firm is now “cautiously optimistic” the deal will go forward, one of the sources said, amid recent indications of a thaw in U.S.-China trade tensions that have seen both sides propose tens of billions of dollars in tariffs.

On Friday, the Trump administration said it had reached a deal that would put ZTE back in business after the Chinese telecommunications company pays a $1.3 billion fine and makes management changes. While that is having problems on the US side, it probably helped clear the way for Qualcomm's deal.