A senior US diplomat insisted on Monday that Washington is committed to enforcing sanctions on Iranian oil sales, citing reports that Iran might be seeking to sell its oil supplies.

“We've seen unconfirmed reports regarding the potential transfer and sale of stored Iranian oil," US deputy special envoy for Iran Abram Paley's office posted on X on Monday. "Our sanctions on Iran's oil remain in place and will be enforced."

The post shared a link to a Dec. 3 US Treasury press release detailing new sanctions against 35 companies and ships over their alleged involvement in Iranian oil sales.

The entities and vessels sanctioned "play a critical role in transporting illicit Iranian petroleum to foreign markets," the Treasury statement said.

Iran International reported about Iran trying to offload unsold oil in China on Friday.

Iran's Islamic Revolutionary Guard Corps (IRGC) is seeking to sell oil stored in China before US president-elect Donald Trump can block sales with tougher sanctions, an informed source had told Iran International.

Iranian authorities instructed the IRGC to sell the sanctioned oil stored at Dalian Port in northeast China through intermediary firms, the source speaking on condition of anonymity said.

US Senate foreign relations committee ranking member Senator Jim Risch, a Republican from Idaho, cited the report in a post on X calling for harsher measures.

"For too long, #China’s purchases of illicit Iranian oil have funded #Iran’s terrorism and human rights abuses," a post on the ranking member's official page said.

"The Biden Admin has already let billions back to Tehran from elsewhere – now's the time to use #SHIPAct sanctions to freeze $1B before the #IRGC cashes out again."

Risch was referring to the Stop Harboring Iranian Petroleum (SHIP) Act which passed with broad bipartisan support and aims to impose restrictions on ports and refineries handling Iranian oil exports.