More than 80 percent of American companies feel China is less welcoming to foreign businesses than in the past, a US business lobby group reported Wednesday, as trade tensions surge between the world's top two economies.

Slowing growth, rising protectionism, and unfair policy treatment for non-Chinese firms have led a vast majority -- 81 percent -- of respondents to the American Chamber of Commerce in China's annual business climate survey to say they felt "less welcome" in the country last year.

The report came as China's President Xi Jinping won acclaim from the global elite at the World Economic Forum in the Swiss resort of Davos for a speech Tuesday in which he defended globalisation and said that protectionism "is like locking oneself in a dark room".

But according to the surveyed companies, protectionism in China has been increasing, with non-Chinese law firms, financial service companies, and real-estate developers complaining of double standards intended to give domestic companies the advantage over foreign firms.

"Globalisation doesn't just mean exporting and buying up foreign assets," the group's chairman William Zarit said in a statement.

"With both the US and China undergoing political transitions, we hope the results of this survey can stimulate healthy debate over China's future."

More than 60 percent of the respondents have little or no confidence that Beijing will open China's markets further in the next three years.

Foreign ministry spokeswoman Hua Chunying said Wednesday that the country "is still a land of attraction for foreign investors", adding that Beijing will "take measures to attract foreign investment, and advanced technologies, and management experiences".

Respondents estimated China's growth this year would be 6.1 percent, compared to an AFP survey forecast of 6.5 percent.

The share of firms saying China was a top-three global priority fell to a record low of 56 percent from a peak of 78 percent in 2012, the chamber said.

China today is "far from being a market economy," Andy Collier of Oriental Capital Research told AFP, noting that the yuan currency is still not widely used for trade and its firms have only started to move overseas.