China's Communist Party wrapped up a key annual economic meeting on Thursday with pledges to carry out a "prudent" monetary policy next year and further open the country to foreign investment.

President Xi Jinping presided over the three-day, closed-door meeting which came at a time when the Chinese economy is slowing and Beijing seeks to close a "phase one" deal with Washington in their protracted trade war.

"China's opening-up will continue to develop on a larger scale and at a deeper level," said a statement published by the official Xinhua news agency at the end of the Central Economic Work Conference.

"Foreign investment will be facilitated and better protected" and the overall level of tariffs will be lowered, the statement said.

China will also shorten its "negative list" of industries that are closed to foreign investment. The list was reduced from 48 to 40 sectors in July.

The government has repeatedly pledged to further open up its economy but US and European companies continue to complain that access to the Chinese market remains difficult.

China has pledged to further open up its economy to foreign investment
China has pledged to further open up its economy to foreign investment AFP / STR

The White House has said tariffs imposed on Beijing in their trade war are aimed at forcing China to change unfair trade practices, including subsidies and theft of intellectual property

Negotiators are working to finalise a pared down trade deal with the threat of new increase in tariffs on billions of dollars worth of two-way trade looming on Sunday.

China is also facing an economic slowdown, with growth dropping to six percent in the third quarter -- its worst performance in 27 years.

The economic conference did not announce any stimulus measures.

"The country will continue to implement a proactive fiscal policy and prudent monetary policy," the statement said.