Chinese Foreign Ministry spokeswoman Hua Chunying said “sanctions” against the four officials would begin Monday, without elaborating. Hua listed Rubio and Cruz—both Republicans and high-profile critics of China—as targets of the unspecified measures, in addition to Sam Brownback, Representative Chris Smith and the Congressional-Executive Commission on China.

The moves come three days after the U.S. sanctioned a top member of China’s ruling Communist Party and three other officials over alleged human rights abuses in Xinjiang, located in the country’s far west. Beijing has repeatedly vowed retaliation over U.S. actions intended to support residents of Xinjiang, Hong Kong and Taiwan, accusing Washington of inappropriately interfering in China’s internal affairs.

The sanctioned individuals include Chen Quanguo, the Xinjiang party secretary who sits on the 25-member Politburo, as well as Zhu Hailun, party secretary of the Xinjiang Political and Legal Committee, and the current and former directors of the Xinjiang Public Security Bureau, the Treasury Department said Thursday.

Both the U.S. moves and Chinese response were largely symbolic, since both groups of officials were unlikely to have much financial or legal exposure to each other’s countries.

The U.S. decision marked the first time the U.S. has sanctioned a sitting Chinese official under the 2016 Global Magnitsky Human Rights Accountability Act, which gives the U.S. broad authority to impose human-rights sanctions on foreign officials. Senior administration officials had been pushing for the sanctions for months but had been stymied by President Donald Trump, who fretted that they would complicate his U.S.-China trade deal.