The U.S. should revive the Trans-Pacific Partnership (TPP) as the deal is the most "important geopolitically" for the U.S., the country's former ambassador to China said.

"There's nothing more important than resurrecting, bringing back the TPP. That's probably the best economic complement we can come up with in the U.S. to deal with South China Sea issues (involving) China," said Max Baucus, the Obama administration's envoy to China from 2014 to January 2017.

President Donald Trump formally withdrew the U.S. from the TPP just days after his inauguration on January 20 this year . The accord between the U.S. and 11 countries in the Pacific region to liberalize trade, set common trade standards and cut barriers was reached in 2015.

The move to exit the deal will not bode well for the U.S. geopolitical presence in Asia, Baucus told CNBC's "The Rundown" on Thursday.