WASHINGTON (REUTERS) - The United States takes all alleged sanctions violations seriously and will take action as appropriate, a State Department spokesman said on Friday (May 17), responding to a question about a tanker unloading Iranian fuel oil at a Chinese port.

Reuters on Thursday reported that a tanker carrying nearly 130,000 tonnes Iranian fuel oil had unloaded the cargo into storage tanks near the Chinese city of Zhoushan.

"The United States takes all alleged sanctionable activities seriously and will take action as appropriate. We are committed to enforcing our sanctions, especially those related to Iran's oil and petrochemicals sectors," a State Department spokesman said in an emailed response.

He said the agency was aware of the specific report about the tanker but declined to comment on it.

The statement came several weeks after US President Donald Trump's administration stepped up moves to choke off Iran's oil exports by scrapping waivers it had granted to big buyers of the country's crude oil, including China.

Refined products like fuel oil, mainly used to power ship engines and generate electricity, were not covered by the temporary waivers granted on the sanctions reintroduced in November 2018.