A new round of trade talks between American and Chinese officials could help bring an end to the global trade war, former U.S. Treasury Secretary Jack Lew told CNBC on Monday, but resolving the remaining sticking points will be a rocky process.

The world's two largest economies have imposed tariffs on billions of dollars' worth of one another's goods over the past year, battering financial markets and souring business and consumer sentiment.

Negotiations between Washington and Beijing have taken longer-than-expected, with officials at times making contradictory comments on their progress.

"I suspect there are some more bumps in the road ahead as the most difficult issues get worked out," Lew told CNBC's Martin Soong at the China Development Forum in Beijing on Monday.

"There is no reason they shouldn't be able to make progress so that you get something done in the window… (But) I don't think it will resolve all issues for all time."

"I think regardless of the language used to describe the agreement, there will still be core issues for the two countries to work through… The job is not to get it done once and for all, it is to keep making progress," Lew said.