Published Mon, Aug 26 2019 2:31 PM EDT

President Donald Trump is raising alarms when it comes to his dealings with the Chinese government, Stephen Roach, a senior fellow at Yale University, told CNBC on Monday.

“The president has almost become unhinged in dealing with China on a day-to-day basis,” the former Morgan Stanley Asia chairman told “Squawk Alley.”

Roach referenced Trump’s whiplash rhetoric on China over the past week. On Friday, Trump referred to Chinese President Xi Jinping as an “enemy,” shortly after China announced it will impose tariffs on $75 billion worth of U.S. goods and reinstate duties on American autos.

Trump then declared that American companies could not longer do business in China and “threw out all sorts of anger-driven responses to China’s retaliation to his latest tariff initiative,” said Roach, one of Wall Street’s leading authorities on Asia.

But Monday, Trump said at the G-7 summit in France that Beijing is ready to reenter negotiations and begin serious talks. At a later press event, Trump said he didn’t want to get into details, saying that talks between U.S. and Chinese trade officials have been taking place at the highest levels.

However, Hu Xiji, editor-in-chief of the Global Times, a tabloid under the People’s Daily, which is the official newspaper of the Communist Party of China, tweeted that Trump was “exaggerating.”

Roach, one of Wall Street’s leading authorities on Asia, has been critical of Trump in the past and his negotiating tactics with Beijing.

“Having gone through this back and forth on the on again-off again trade deal, the president and his advisors have really lost their credibility in assessing the state of play in this trade conflict,” Roach said.

A White House spokesman was not immediately available to respond to Roach’s comments.