Cisco’s $2.6 billion Acacia Communications acquisition still doesn’t have regulatory approval from China, and that approval represents the final hurdle preventing the two companies from closing the deal.

In a joint statement today, the two companies said they remain “actively engaged” with the State Administration for Market Regulation of the People’s Republic of China (SAMR) and expect the acquisition to receive regulatory clearance. But they also note that the United States, Germany, and Austria previously signed off on the deal. Only SAMR approval remains.

The companies don’t address the ongoing trade and political tensions between the U.S. and China in the joint statement, but it’s worth noting that the two countries’ escalating war of words (and supply-chain components) includes a U.S. push to restrict Chinese access to U.S. intellectual property and to manufacture semiconductors and related technologies domestically.

Cisco announced a deal to buy the small optical company in July 2019 and expected the acquisition to close by the end of last year. Acacia makes high-speed coherent optical interconnect products for webscale companies, service providers, and data center operators. Cisco already uses its technology in some of its optical systems and routers. The acquisition brings it in house.

“The market that Acacia plays in for coherent technology is a multi-billion market,” Bill Gartner, SVP and general manager of Cisco’s Optical Systems and Optics Group, said in an earlier interview with SDxCentral. “We are a relatively small player in that market, but we think this expands the opportunity for optical systems.”

Acacia also plays a major role in Cisco’s 5G strategy, which centers on operators’ need to build new backhaul infrastructure to carry 5G traffic and select a vendor to supply a 5G mobile network packet core. Cisco targets this space with its routers and optics technology, a market it entered in 2010 with its CoreOptics acquisition, followed later by acquisitions of Lightwire, Luxtera, and most recently Acacia.