The head of a US congressional delegation visiting China said on Thursday that much needs to be done to resolve the trade conflict between the two countries, which he said is creating difficulties for companies on both sides of the Pacific.

A lot of business is going on between the world's two largest economies despite the trade war, Adam Smith, a Democrat Representative from Washington state, said on the final day of a five-day trip.

"We have a lot of work to do to resolve those issues, but China, the US and the world can benefit from resolving some of our differences and working better together," he said after a meeting with the American Chamber of Commerce in Shanghai.

Smith also repeated his call from the outset of the trip for more communication between the China and US militaries.

"Two of the largest nuclear powers in the world need to be talking to each other, particularly considering the fact that we do have some disagreements," he said.

Smith said the main purpose of the trip was to open up lines of communication between the two governments. (AP)