Imran Khan had refused to comment on Uighurs in China.

Highlights Top US diplomat questioned why Imran Khan was not speaking out on China

Mr Khan had said Pak would raise issues with China only in private

China is a major diplomatic and economic partner of Pakistan

In a snub to Pakistan Prime Minister Imran Khan, a top US diplomat on Friday questioned why Mr Khan was not speaking out about China, which has detained an estimated one million Uighurs and other Turkic-speaking Muslims.

Amid increased tensions between India and Pakistan after New Delhi scrapped Article 370 of the Constitution, which grants special status to Jammu and Kashmir, Alice Wells, US Acting Assistant Secretary for South and Central Asia said Mr Khan's comments on Kashmir were unhelpful. "A lowering of rhetoric would be welcome, especially between two nuclear powers."

She also questioned why Mr Khan was not also speaking out about China, which has detained an estimated one million Uighurs. "...I would like to see the same level of concern expressed also about Muslims who are being detained in Western China, literally in concentration-like conditions. And so being concerned about the human rights of Muslims does extend more broadly than Kashmir, and you've seen the administration very involved here during the UN General Assembly and trying to shine a light on the horrific conditions that continue to exist for Muslims throughout China," she said.

China is a major diplomatic and economic partner of Pakistan.

Mr Khan, asked about the Uighurs at a think tank on Monday, declined comment, saying that Pakistan had a "special relationship" with China and would only raise issues in private.

Rights groups and witnesses say that China has been trying to forcibly stop Islamic traditions and integrate Uighurs into the majority Han population. China says it is providing vocational training and discouraging extremism.

US sought to use the annual United Nations summit to build up international pressure on China over its treatment of the Uighurs.

The State Department had organised an event on Tuesday to highlight the plight of Uighurs in China. The conference was held on the sidelines of the General Assembly to garner support "to demand and compel an immediate end to China's horrific campaign of repression," John Sullivan, the US's second-highest diplomat, said.

"We cannot be the only guardians of the truth nor the only members of the international community to call out China and demand that they stop," Mr Sullivan added.

On Tuesday, US President Donald Trump also fired several shots across the bow of the fellow Security Council member, moving beyond his typical attacks against China on international trade.

"The world fully expects that the Chinese government will honor its binding treaty... (and) protect Hong Kong's freedom and legal system and democratic ways of life," Mr Trump told the General Assembly.

"How China chooses to handle the situation will say a great deal about its role in the world and the future," the Republican tycoon added during his third appearance at the diplomatic forum in New York.

It marked one of his most strident speeches on the situation in Hong Kong since massive anti-government protests broke out there three months ago. The demonstrations have triggered the Asian financial hub's biggest political crisis since its handover from Britain to China in 1997.