France and other European countries support a European-led naval mission to ensure safe shipping through the Strait of Hormuz, a strategic point in the Gulf which sees a fifth of the oil consumed worldwide passing through.
On Monday, British Foreign Secretary announced plans to develop and deploy a "maritime protection mission" but gave few details.
Iran seized the British-flagged tanker Stena Impero on Friday in the Gulf's Strait of Hormuz, which sees a fifth of the oil consumed worldwide passing through it.
Tensions have soared in the Gulf as Iran ramped up its controversial nuclear programme, following the United States’ pulling out of the nuclear deal signed by Iran and world powers in Vienna in 2015.
The US has called for stepping up efforts to safeguard the Gulf waters. France has engaged in intense diplomacy.
"This is the opposite of the American initiative which is about maximum pressure to make Iran go back on a certain number of objectives," French Foreign minister Jean-Yves Le Drian told parliament on Tuesday, after a meeting in Paris with Iran’s deputy foreign minister Abbas Araghchi.
"We need to put in place as process of de-escalation to reduce the tensions," said Le Drian. "We are now pushing Iran to return to the Vienna agreement.”
Iranian media said Araghchi had brought an unspecified message from Iran’s President Hassan Rouhani for French president Emmanuel Macron, whom he met later on Tuesday.
The EU confirmed Iran would meet envoys from the remaining parties in the deal - France, Britain, China, Germany and Russia - in Vienna on Sunday.
Contact with ship’s crew
The owner of Stena Bulk, meanwhile, says it has made contact with the crew. The ship's master said "that everyone was safe with good cooperation with the Iranian personnel onboard."
The 23 crew are mostly Indian, but also include Filipino, Russian and Latvian nationals.
The owners consider the contact as a good sign. President Hassan Rouhani suggested Iran might release the ship if Britain takes steps to release an Iranian oil tanker it seized off Gibraltar earlier this month.