Turkey is seeking permission from Iranian authorities for 11 Turkish-owned ships to pass through the Strait of Hormuz, the country’s transportation minister said on April 1.

A total of 14 Turkish-owned ships remain in the strait, Abdulkadir Uraloglu told reporters in Ankara, adding that three are there for ongoing operations, including power generation, and are not asking to leave.

“Discussions are ongoing” for the others, he said, stating that Turkish authorities are in regular contact with the ships’ crews.

About a fifth of the world’s oil and gas supply passes through the strait. After Israel and the U.S. commenced bombing of Iran on February 28, Iran effectively blocked the waterway and strangled that supply, as well as those of other goods, including fertilizer and metals.

Only one Turkish-owned ship has received permission to pass through Hormuz since the start of the conflict, and that was “because it had used an Iranian port,” Uraloglu said earlier this month.

“One of the main dangers facing our region is not only the prolongation of the war but also the risk of it turning into a regional conflict,” Turkish President Recep Tayyip Erdogan said in parliament on April 1. “Retaliatory attacks targeting energy, transport and civilian infrastructure are unfortunately increasing this risk.”

Brent crude has jumped about 42% since the war began, despite swinging in response to mixed messages about when and how the fighting might end.

Prices slipped on Wednesday as President Donald Trump indicated that the U.S. could withdraw from the conflict within two or three weeks.