The Trump administration’s stated goal is to extract a nuclear deal from Iran that is more favorable to American interests than the 2015 agreement that President Trump abandoned last year. Critics say, however, the administration has only undermined any path to diplomacy by making demands that Iran cannot accept.

The Iranians, in turn, have taken steps to renege on their commitments under the 2015 deal and have threatened to violate the agreement further unless European countries that co-signed the deal offer some relief from the sanctions. The Europeans have made clear that they hope to preserve the deal, but they have not been able to give a meaningful boost to Iran’s economy, which is reeling under the weight of the sanctions.

That has led to a split between Europe and the United States despite their common interest in making sure crucial oil shipping routes in the Persian Gulf are protected against Iranian and other threats. The Trump administration has sought to rally a maritime force to escort ships through the Gulf, but European nations have distanced themselves from the effort, and Germany has outright said no.

The latest foreign vessel Iran said it had seized received fuel from other ships and had been transporting it to Arab countries in the Persian Gulf, the commander of Iran’s Second Marine Corps said to Iran’s semiofficial Fars News Agency. The ship was detained in coordination with judicial authorities, he said.

The commander said the ship had been carrying about 700,000 liters of fuel, about 185,000 United States standard gallons. Fars said on Twitter that seven foreign nationals had been detained. The Mehr news agency reported that the ship had been seized near Farsi Island, a tiny, barren Iranian territory northwest of the Strait of Hormuz.