Max Baucus, former U.S. ambassador to China, warned Tuesday that Beijing may be able to endure more hardship than Washington in their yearlong trade war.

"The Chinese are so tough, they can withstand more pain, in my judgement, than can Americans," said Baucus, also a Democratic former senator from Montana. He was appointed ambassador by former President Barack Obama.

"The Chinese respect strength more than any other people. ... I think they can smell weakness better than any other people," Baucus said, but said currently China appears to be hurting more economically than the U.S.

Baucus appeared "Squawk Box," before U.S. trade officials announced shortly after stocks opened lower Tuesday that certain items were being excluded from President Donald Trump's upcoming 10% tariffs on the $300 billion of Chinese imports not already taxed. Other items subject to additional tariffs — set to go into effect Sept. 1 — are being delayed until mid-December, including smartphones. The Dow Jones Industrial Average, led by Apple, surged more than 500 points, or 2%, on the news.

On Tuesday, Chinese officials said they had a trade call with U.S. Trade Representative Robert Lighthizer and Treasury Secretary Steven Mnuchin. China said it agreed to another call in two weeks.

Chinese President Xi Jinping also faces pressure from pro-democracy protests in the Chinese territory of Hong Kong, Baucus said. Thousands of demonstrators disrupted operations at Hong Kong International Airport for the second day on Tuesday. The former U.S. ambassador expects the unrest to escalate as protesters "tasted victory."

State media outlets in China warned that Hong Kong demonstrators are "asking for self-destruction" as they released a video showing Chinese military vehicles amassing near the border of the city.