There's a '50-50' chance of a trade deal at the G-20, says former US ambassador

• At the previous G-20 summit in Argentina, the two leaders agreed on a 90-day trade ceasefire that put their tariff war on hold for months until last week.
• "So far, President Trump has been hot and cold — he says things are great one day, and then he blames China the other day, so that's very hard to tell," former U.S. ambassador to China, Max Baucus, said Wednesday about the prospects of a deal at the G-20 summit in June.

China's President Xi Jinping and U.S. President Donald Trump attend a welcome ceremony at the Great Hall of the People in Beijing on November 9, 2017.

Nicholas Asfouri | AFP | Getty Images

Investors will be closely watching the G-20 summit in Japan next month, as U.S. President Donald Trump and Chinese President Xi Jinping are set to meet amid their escalating trade war — but the odds of striking a deal at that meeting "are about 50-50," said a former U.S. ambassador to China.

"So far, President Trump has been hot and cold — he says things are great one day, and then he blames China the other day, so that's very hard to tell," Max Baucus told CNBC's "Squawk Box" on Wednesday.

At the previous G-20 summit in Argentina last December, the two leaders agreed on a 90-day trade ceasefire that put their tariff war on hold for months — until last week.

Last Friday, the U.S. more than doubled tariffs on $200 billion of Chinese goods in the midst of ongoing negotiations, prompting China to retaliate with its own set of tariffs. Beijing announced Monday that more than 5,000 American products could see duties rise as high as 25% from June 1.

This very public approach has put both countries in a very difficult position because it's very hard to back down now.

Max Baucus

Former U.S. ambassador to China

Baucus said the upcoming U.S. presidential election in 2020 will also be a factor in the ongoing trade negotiations.

"I frankly wonder, it's very possible that President Trump will strike a deal before 2020. That will especially happen if the stock market is going south because he likes a solid stock market," said Baucus, who is also a former U.S. democratic senator from Montana.

But Trump is caught "in a bit of a box" as "he doesn't want to appear weak," said Baucus. "If he appears weak, he will be criticized by the democratic presidential nominee and other democrats, so he's in a bit of a box."

In particular, the public nature of the trade dispute has made a resolution more difficult, he said.

"This very public approach has put both countries in a very difficult position because it's very hard to back down now," said Baucus.

"China wants to do business with the United States. China wants a deal, but China wants a deal that China can live with," said Baucus.