Former U.S. Secretary of State Henry Kissinger on Wednesday heavily criticized the "extremely deplorable" language about China used by both U.S. presidential candidates in their campaign ads.

"I have seen these advertisements with the two candidates competing with each other on how to deal with a cheating China. And both used the word cheat as applied to China," Kissinger said at the Washington-based Woodrow Wilson Center.

He said that he was "bothered" by the fact that both U.S. presidential candidates are "appealing to suspicion of China" in their campaigns.

Kissinger, who has endorsed Republican presidential nominee Mitt Romney, said he opposed Romney's promise to label China as a currency manipulator. He added that "among the community of people who actually deal with China," almost all of them oppose Romney's idea.

"The theoreticians who have other views wanted to turn the whole thing into a crusade," said Kissinger. "But they haven't actually studied China or dealt with China."

He said that hostile rhetorics targeting China are nothing new during the presidential campaigns in his country, citing as examples former U.S. Presidents Ronald Reagan and Bill Clinton.

But Kissinger believed with "confidence" that once in office, the new U.S. president, "looking at realities," will work to build a cooperative relationship with China.

Kissinger made a secret visit to China in July 1971, paving the way for a groundbreaking 1972 meeting in Beijing between then U.S. President Richard Nixon and late Chinese leader Mao Zedong. The visit opened a door for China-U.S. relations that had been closed for decades.