HONG KONG — The U.S. government has blacklisted Chinese smartphone maker Xiaomi Corp. and China’s third-largest national oil company for alleged military links, heaping pressure on Beijing in President Donald Trump’s final week in office.

The Department of Defense added nine companies to its list of Chinese firms with military links, including Xiaomi and state-owned plane manufacturer Commercial Aircraft Corp. of China.

U.S. investors will have to divest their stakes in Chinese companies on the military list by November this year, according to an executive order signed by Trump last November.

Xiaomi did not immediately respond to a request for comment.

Xiaomi Corp. overtook Apple Inc. as the world’s No. 3 smartphone maker by sales in the third quarter of 2020, according to data by Gartner. Xiaomi’s market share has grown as Huawei’s sales have suffered after it was blacklisted by the U.S. and its smartphones were cut off from essential services from Google.

Separately, the Commerce Department put China National Offshore Oil Corp. on the entity list, an economic blacklist that forbids U.S. firms from exporting or transferring technology with the companies named unless permission has been obtained from the U.S. government.

CNOOC has been involved in offshore drilling in the disputed waters South China Sea, where Beijing has overlapping territorial claims with other countries including Vietnam, the Philippines, Brunei, Taiwan and Malaysia.

Chinese state-owned company Skyrizon was also added to the economic blacklist, for its push to “acquire and indigenize foreign military technologies,” U.S. Commerce Secretary Wilbur Ross said.

Meanwhile, the official Xinhua News Agency reported Friday that President Xi Jinping sent a letter to former Starbucks CEO Howard Schultz asking him to help repair U.S.-Chinese relations in a rare direct communication from China’s paramount leader to a foreign business figure.