US Vice President Joe Biden on Thursday criticised China's tightening of controls on foreign journalists, days after British Prime Minister David Cameron reportedly aired similar concerns when he met the country's president.

In a wide-ranging address to about 60 American business leaders in Beijing, Biden said that the US and China still have "many disagreements", including some he described as "profound" such as on "the treatment of US journalists".

"Innovation thrives where people breathe freely, speak freely, are able to challenge orthodoxy, where newspapers can report the truth without fear of consequences," Biden said on the second day of a two-day visit dominated by discussion of Beijing's move to expand its military influence in the skies over the East China Sea.

He added that "there are many more steps China can take to open its politics and society as well as its economy", but did not elaborate.

China's one-party state imposes tight restrictions on domestic media, and authorities stress that foreign news organisations are subject to Chinese law within the country.

At a regular press briefing in Beijing Thursday, foreign ministry spokesman Hong Lei said China provides "a very convenient environment for news coverage for foreign media".

"As long as you are objective and just, I think an objective conclusion can be reached on that," he added.

Earlier this week a reporter for New York-based Bloomberg news agency -- which is embroiled in controversy over an unpublished article on a tycoon's links to senior Communist figures -- was barred from attending a joint event with Cameron and Premier Li Keqiang.

Cameron personally raised the matter with President Xi Jinping, according to multiple reports, but Chinese authorities have denied that the move was intended to target Bloomberg.

Both Bloomberg and the New York Times have had their websites blocked in China after they published investigations last year into the family wealth of Xi and former premier Wen Jiabao, respectively.