China on Thursday warned the Donald Trump-fronted US Republican Party against making "groundless accusations" after it accused Beijing of cultural genocide and said its economy was based on piracy.

The GOP said in its 2016 platform that Beijing made "a preposterous claim to the entire South China Sea", adding that "cultural genocide continues" in the regions of Tibet and Xinjiang.

"The currency is manipulated, our technology is stolen and intellectual property and copyrights are mocked in an economy based on piracy," it added.

Chinese foreign ministry spokesman Lu Kang called on the party to "stop their groundless accusations against China and interference in China's domestic affairs", in a statement carried by the official Xinhua news agency.

"All political parties in the United States should view China's development in an objective and rational manner," he added, in Beijing's first comments on the Republican Party since Donald Trump's nomination as its presidential candidate on Wednesday.

The United States and China are the world's two largest economies with deep trade ties, but tensions remain over security and human rights issues.

China has been seen as sceptical of Democratic candidate Hillary Clinton, a consistent critic of Beijing's rights record who last year slammed its detention of feminist activists as "shameless".

As secretary of state, Clinton also oversaw the US "pivot" to Asia, which many in China see as an effort to contain Beijing's rising influence in the region.

US politicians have long criticised China's human rights record, taking Beijing to task for its treatment of ethnic minorities in the mostly Muslim, western region of Xinjiang and in Tibet.

Economic and trade issues have also been a frequent point of discord. The US government under President Barack Obama has censured Beijing for overlooking intellectual property theft from American companies and the manufacture of pirate goods.

The Republican Party has often received a warmer reception in Beijing, seen as more focused on trade and with historical ties to Richard Nixon, who engineered a detente between the two powers.

But Trump has also made China-bashing a staple of his campaign, saying the country was "raping" the US through trade and calling for tariffs of 45 percent on Chinese goods.

China's finance minister Lou Jiwei reportedly called Trump an "irrational type" in April, suggesting Beijing was uncomfortable with the Republican's tone under his leadership.