Charterers are paying three times as much to ship Russian crude from Kozmino to China following US sanctions on 183 more ships last week.

Traders told Bloomberg that Chinese importers are fixing tankers for between $5m and $5.5m for a short trip that used to cost $1.5m.

These rates are expected to rise even further as buyers source more mainstream ships for Espo crude cargoes from the east coast port.

Ships under sanction by the US accounted for 22% of the crude oil moved at sea last year, according to the International Energy Agency.

Most of the tankers serving Kozmino are aframaxes, which can carry up to 750,000 barrels.

Overall global aframax rates were assessed at $24,200 per day by the Baltic Exchange on Wednesday, down 9% from the day before.

Shipping data shows that sanctions have had an immediate effect, with blacklisted vessels idling off China with Espo and Sokol crude.

Shandong Port Group has said it will not handle sanctioned tankers.

Bloomberg reported that the amount of oil stranded off the Chinese coast is growing, having doubled from earlier this week.

Five tankers carrying almost 4m barrels of Espo and Sokol oil have not docked. Four of these were designated by the US.

Theoretically, importers can still discharge Russian crude loaded on sanctioned tankers before Friday’s US measures were announced.

But many are wary of entangling themselves in the US sanctions net despite this.

Market watchers have tipped an increase in ship-to-ship transfers as blacklisted tankers seek to offload cargoes at sea.