China announced "corresponding sanctions" against the United States on Monday, after Washington penalised senior Chinese officials over the treatment of minority Uighur Muslims in the western region of Xinjiang. China's move came as relations between the world's two biggest economic powerhouses slumped over disagreements on issues including the coronavirus pandemic, trade, Huawei, and a sweeping national security law imposed on Hong Kong. The sanctions targeted US senators Ted Cruz and Marco Rubio, US Representative Chris Smith, Ambassador at Large for International Religious Freedom Sam Brownback, and the US Congressional-Executive Commission on China. Mr Rubio and Mr Cruz have both sponsored legislation that would punish China's actions in Xinjiang. Mr Smith has also been a vocal critic of China on issues ranging from Xinjiang to Hong Kong and the coronavirus. All three are members of the Republican Party. The Congressional-Executive Commission on China monitors human rights and the development of the rule of law and submits an annual report to Mr Trump and Congress. "The US actions seriously interfere in China's internal affairs, seriously violate the basic norms of international relations and seriously damage Sino-US relations," Chinese Foreign Ministry spokeswoman Hua Chunying said. "China will make further responses based on how the situation develops." She did not elaborate. UN experts and activists said at least a million ethnic Uighurs and other Muslims are held in detention centres in Xinjiang. China describes the facilities as training centres helping to stamp out terrorism and extremism and give people new skills. Washington announced its measures against Chinese officials including the Communist Party secretary of Xinjiang, Chen Quanguo, on Thursday. The sanctions were imposed under the Global Magnitsky Act, which allows the US government to target human rights violators worldwide by freezing any assets in the US, prohibiting Americans from doing business with them, and banning them and their immediate family from travelling to the US. Mr Rubio described the move as "long overdue" and said that more steps were needed. "For far too long, Chinese officials have not been held accountable for committing atrocities that likely constitute crimes against humanity," he said.