Trade.

On the Chinese trade surplus:

Concern has grown among US producers at the scale of Chinese imports and limits have been put on a range of goods.

The US has threatened to impose more quotas if Chinese exports keep rising.

On trade barriers:

"Today, I broaden the challenge by making this pledge: The United States is ready to eliminate all tariffs and subsidies and other barriers to the free flow of goods and services as other nations do the same.

The elimination of trade barriers could lift hundreds of millions of people out of poverty over the next 15 years."