Global oil prices jumped to $105 a barrel, the highest point since 2014, as the Russian invasion of Ukraine led to fears of disruption to world supplies.

Although the West has not threatened direct sanctions on Russia’s energy exports, but other sanctions can impact deliveries.

"If sanctions affect payment transactions, Russian banks and possibly also the insurance that covers Russian oil and gas deliveries, supply outages cannot be excluded," Reuters quoted Commerzbank analyst Carsten Fritsch as saying.

At least three major buyers of Russian oil were unable to open letters of credit from Western banks to cover purchases on Thursday, sources told Reuters.

Analysts believe that Brent is likely to remain above $100 a barrel until significant alternative supplies become available from OPEC, US shale or Iran, for example.

Negotiations over Iran’s expanding nuclear program since last April continue with no final result. Although progress has been made, diplomats say some significant issues remain to be resolved. An agreement will lift US sanctions and allow Iran to add to global oil supplies, although its capacity remains limited.

Analysts are warning of inflationary pressure on the global economy from $100 oil, especially for Asia, which imports most of its energy needs.

China has been buying more Iranian oil clandestinely in defiance of US sanctions reportedly building up its reserves in past few months.