The opposition-run National Assembly appointed the 15-member Citgo board early this year after Guaido declared presidential powers, arguing that Maduro's re-election was illegitimate. Maduro maintains power with backing from the military and allies such as Cuba, Russia and China.
China would continue to cooperate with Venezuela, ministry spokeswoman Hua Chunying said in a statement issued late on Wednesday, and urged the United States to respect international law and stop trying to stir up discord.
Representatives of the ruling Socialist Party met with adversaries of President Nicolas Maduro this week in Barbados as part of talks that began in Norway in May to resolve a stalemate resulting from Maduro's disputed 2018 re-election.
Opposition leader Juan Guaido, who has been recognized as Venezuela's rightful leader by more than 50 governments, has said any talks must lead to a sustained solution to the crisis and cannot be used by the Socialist Party to buy time.
When Guaido, the speaker of the National Assembly, proclaimed a rival presidency in January in a bold challenge to Maduro, he injected new hope into Venezuela's fragmented opposition. With most Western nations saying Maduro's reelection last year was rigged, Guaido cited the constitution to announce an interim presidency until fresh elections could be held.
The uprising has not managed to turn the military, which has continued to prop up Maduro, who is also supported by China, Russia and Cuba. But unbridled inflation, rampant shortages and crumbling infrastructure make daily life miserable for the masses.