People protest at a Uighur rally on February 5, 2019 in front of the US Mission to the United Nations, to encourage the State Department to fight for the freedom of the majority-Muslim Uighur population.

U.S. President Donald Trump's comments that a trade deal with China might have to wait until late 2020 raised fresh doubts on when the dispute might end, while a U.S. House bill targeting camps for Muslims in Xinjiang drew Beijing's ire.

"In some ways, I like the idea of waiting until after the election for the China deal. But they want to make a deal now, and we'll see whether or not the deal's going to be right," Trump told reporters in London on Tuesday, triggering a sharp fall in stocks and a flight to government bonds.

The U.S. House of Representatives' approval of a bill requiring the Trump administration to toughen its response to China's crackdown on Uighur Muslims in the western region of Xinjiang could deal another setback to the trade negotiations.

The Uighur bill, which was passed 407-1 in the Democratic-controlled House, requires the U.S. president to condemn abuses against Muslims and call for the closure of mass detention camps in Xinjiang. It calls on Trump to impose sanctions for the first time on a member of China's powerful politburo, Xinjiang Communist Party Secretary Chen Quanguo.

Beijing called the bill a malicious attack on China, demanded the United States keep it from becoming law and said it would act to defend its interests as necessary.