DUBAI (Reuters) – Iran’s foreign minister accused the United States on Twitter on Saturday of engaging in “piracy and threats” to stop Tehran from selling oil to traditional clients, after Washington blacklisted an Iranian oil tanker that it said was headed to Syria.

U.S. Secretary of State Mike Pompeo said on Friday the United States had reliable information the Iranian oil tanker Adrian Darya, which the U.S. Treasury Department has blacklisted, was headed to Syria.

“US engages in piracy & threats to prevent Iran from selling oil to traditional customers,” Mohammad Javad Zarif tweeted. “Stop nagging @SecPompeo: We will sell oil to any & all buyers.”