Britain's decision comes after a similar step by the US.

America on Monday, May 18 extended a sanctions waiver ​allowing purchases of Russian seaborne oil to support energy-vulnerable countries experiencing supply disruptions tied to the conflict in the Middle East and the closure of the critical Strait of Hormuz trade route, through which 20% of global oil trades passes.

But the US decision has been met with criticism as some say the decision to extend waivers has allowed the Kremlin to earn more money and fund the war in Ukraine.

Sanctions have sought to curb Moscow's energy revenues since its invasion of Ukraine in 2022, but Russian crude continues to flow to global markets, often via intermediaries.

Brent crude on Tuesday was trading around $110 a barrel, near recent highs, reflecting concerns over disrupted flows through the strait, Reuters news agency reported.

Fuel costs have affected the global economy and placed pressure on the aviation industry. Jet fuel prices have surged in recent months. Fuel can account for up to a quarter of operating expenses for airlines.

Carriers worldwide have responded with fare increases, capacity cuts and warnings of weaker earnings.

Higher fuel costs have also added to cost-of-living pressures in Britain. The government is seeking to ease these pressures as it grapples with inflation ​and energy affordability concerns.

The licence issued on Tuesday, May 19 grants exemptions where the fuels are processed in third countries but includes conditions such as record-keeping requirements for companies.

The new rules take effect on Wednesday, May 20 and will be of indefinite duration.

They will, however, be reviewed periodically and can be amended or revoked, the government said in a notice.

Separately, Britain on Tuesday issued a time-limited licence covering the maritime transportation of liquefied natural gas from Russia's Sakhalin-2 and Yamal projects and related services - including shipping, financing and brokering - under Russia sanctions rules, running ⁠until January ​1 next year.