The FCC has voted unanimously to deny China Mobile's application to provide telecommunications services in the U.S. due to concerns about national security and law enforcement risks.

Why it matters: The move represents a significant escalation in the slow-building conflict between the U.S. and China over telecommunications trade, and comes at a crucial time in U.S.-China trade negotiations. On Friday, the U.S. will raise tariffs on $200 billion of Chinese imports from 10% to 25%. The Chinese government has signaled that it will retaliate.

The bigger picture: The Trump administration has already blocked Chinese telecom equipment maker Huawei from selling to American companies on national security grounds, driven largely by fears that China could use 5G network equipment to spy on Americans, Axios' Kim Hart reported last month.

China is seen as the country to beat in deploying next-generation wireless infrastructure. Last week the FCC unveiled efforts to give the U.S. a leg up in the 5G race against China.

Details: China Mobile's application, submitted in 2011, requested permission to provide telecom services in the U.S., including connecting calls between the U.S. and the vast majority of countries, which would involve interconnecting with American internet networks.