(Recasts, adds details throughout on North Korea missile tests, Trump tweet, quotes from Chinese official)
BEIJING, July 31 (Reuters) - There is no link between North Korea's nuclear program and China-U.S. trade, a senior Chinese official said on Monday, after U.S. President Donald Trump said China had done nothing for the United States on North Korea.
Trump, in tweets on Saturday, said America's "foolish past leaders" had allowed China to make billions of dollars a year in trade and that he was disappointed in Beijing for not solving the problem.
Trump made the comments after North Korea said it had conducted another successful test of an intercontinental ballistic missile (ICBM) that proved its ability to strike America's mainland.
Chinese Vice Commerce Minister Qian Keming, asked about Trump's tweets at a news conference in Beijing, said there was no link between North Korea and China-U.S. trade.
"We think the North Korea nuclear issue and China-U.S. trade are issues that are in two completely different domains. They aren't related. They should not be discussed together," Qian said.
"China will continue to work together with the international community to promote the denuclearisation of the Korean peninsula, and China is also willing to work with the U.S. side for more balanced development of the bilateral trade relationship," he added.
China has repeatedly said it is not Beijing's responsibility to resolve the North Korean issue, and that Washington and Pyongyang both need to take steps to calm tensions and address each others concerns.
China says it fully enforces U.N. resolutions against North Korea, and has condemned unilateral U.S. sanctions on Chinese companies as unhelpful.
The United States and China failed earlier this month to agree on major new steps to reduce the U.S. trade deficit with China, casting doubt over Trump's economic and security relations with Beijing. (Reporting by Beijing Monitoring Desk and Elias Glenn; Writing by Ben Blanchard; Editing by Kim Coghill and Lincoln Feast)