US Secretary of State John Kerry and his Chinese counterpart Wang Yi had a tense exchange over the protests in Hong Kong ahead of their meeting in Washington on Wednesday afternoon.

Speaking to reporters side by side before entering the meeting at the State Department, Mr Kerry had voiced US support for the protesters only for Mr Wang to ask US to stay out of China's affairs.

"The Chinese government has very firmly and clearly stated its position. Hong Kong affairs are China's internal affairs," Mr Wang said, adding that no country would put up with "illegal acts that violate the public order".

Mr Kerry has reiterated Washington's calls for Hong Kong authorities to show restraint.

"As China knows we support universal suffrage in Hong Kong, in accordance with the basic law and we believe in an open society with the highest possible degree of autonomy and governed by rule of law is essential for Hong Kong's stability and prosperity," he said.

"We have high hopes that the Hong Kong authorities will exercise restraint and respect the protesters right to express their views peacefully."

The leaders were in talks on Wednesday to prepare for President Barack Obama's trip to China in November, but the issue of the Hong Kong protests - which escalated over the weekend, was expected to feature prominently.

The protesters, mostly students, are calling for greater autonomy in selecting candidates for Hong Kong's chief executive, after Beijing ruled about a month ago that it would vet candidates before they run for Hong Kong's leadership in 2017.

Protesters have also called for the resignation of Hong Kong's current chief executive Leung Chun Ying, who, during a National Day reception appealed for "society to work with the government to use a peaceful, legal, rational and pragmatic method" to complete the constitutional reform.

On Monday, the White house backed calls by protesters for greater autonomy, saying it "supports universal suffrage in Hong Kong in accordance with the basic law and we support the aspirations of the Hong Kong people".

White House Press Secretary Josh Earnest added:" We also believe the legitimacy of the Chief Executive will be enhanced if the election provides the people of Hong Kong a genuine choice of candidates that are representative of the people's and the voter's will."

Clashes between protesters and the police had broken out on Sunday, resulting in the use of pepper spray and tear gas, but since then, the police presence has died down considerably.