BEIJING, Aug. 28 -- China and the United Statesheld a fresh round of negotiations on a bilateral investment treaty here from Monday to Friday.

They continued to discuss negative lists, which will outline sectors closed to foreign investment, said a brief notice on the website of the Ministry of Commerce.

This was the 20th round of investment treaty talks between the two sides since they began in 2008, as China and the United States sought to increase mutual investment, which only accounted for a tiny share of their respective overseas investment.

It was not until the 2013 China-U.S. Strategic and Economic Dialogue meetings that the talks entered a meaningful phase after the two countries agreed to negotiate on the basis of a negative list approach.