Washington - China is on course to catch up with the United States and join the front ranks of world economic powers, but that is little cause for concern even among Americans, a global survey said Monday.

Most respondents in 13 countries agreed it was "likely that someday China's economy will grow to be as large as the US economy," according to the opinion poll by the Chicago Council on Global Affairs and WorldPublicOpinion.org.

"What is particularly striking is that despite the tectonic significance of China catching up with the US, overall the world public's response is low key -- almost philosophical," said Steven Kull, editor of WorldPublicOpinion.org.

But the poll showed there is also distrust of China to "act responsibly" in world affairs. 

In no country was there a majority who felt that China's economic rise would be mostly negative, but that was not because China is particularly trusted, the pollsters said.

Majorities in 10 out of 15 countries said they did not trust China "to act responsibly in the world." But the same number also said they distrusted the United States.

"Though people are not threatened by the rise of China, they do not appear to be assuming that it will be a new benign world leader," Kull said.

"They seem to have a clear-eyed view that China is largely acting on its own interests."

The Chinese themselves are among the more skeptical populations, with only half saying that their economy will catch up with the United States'. Among Americans, the percentage was 60 percent.

Only in India and the Philippines did a plurality of respondents say the United States would always remain a bigger economy than China.

The highest level of concern about the implications of China's economic march was in the United States, where one in three is worried.

But 54 percent of Americans said that its rise would be "neither positive nor negative" while one in 10 said it would be mostly positive.

Only in Iran did a majority -- 60 percent -- say that it would be "mostly positive for China to catch up."

The survey included 18 countries: Australia, Argentina, Armenia, China, France, India, Iran, Israel, Mexico, Peru, the Philippines, Poland, Russia, South Korea, Thailand, Ukraine, and the United States, plus the Palestinian territories.

Not every question of the poll was asked in each country, so that the results for some questions covered less than 18 countries.