Croatia has requested also US assistance in the search for the missing Croatian seaman Dino Miskic, who has gone missing after his Bourbon Rhode ship sank in the Atlantic, Croatia's Foreign and European Affairs Minister Gordan Grlic Radman said on Monday.

“As soon as we have new information, we will let you know,” the minister said when asked if the US had responded to Croatia’s request.

“It is a fact that we all care, that’s for sure. It is our obligation and duty,” the minister said, stressing that Croatian authorities had been involved in the search for the missing seaman 24 hours a day.

Speaking to reporters on Sunday, Grlic Radman said that together with the family and friends of the missing Croatian sea captain he believed that Miskic was alive and that not all options had been exhausted.

The minister recalled that Zagreb had also sent a request to French authorities, all merchant ships and airplanes passing through and above the area where the vessel sank.

“A search operation as extensive as this one did not happen in the last 20 years. An area of 110,000 square kilometres has been searched, which is twice the size of Croatia,” the minister told a news conference.

The Bourbon Rhode, with a 14-member crew on board, sank on September 26 in the Atlantic, about 2,000 kilometres from the nearest mainland, the French island of Martinique. The crew were mostly Ukrainians and it also included one Russian, one South African and one Filipino. The captain was Dino Miskic, a Croatian national.

The search operation lasted for a week and resulted in the discovery of three crew members who were alive and four members who died. No other bodies have been found since October 1.

The Seafarers’ Union of Croatia has called for the continuation of the active search for the seven missing seamen, noting that life rafts have not been found and that that gives them reason to believe the missing seamen could still be alive.

President Kolinda Grabar-Kitarovic has written to her French counterpart Emmanuel Macron, asking that the decision to suspend the active search be reconsidered.