The International Energy Agency (IEA) said last month that sanctions imposed so far had only had a “limited impact” on Russian production, with rising demand from countries such as India, China and Turkey offsetting falls elsewhere.
A UK ban on Russian oil imports does not come into force until the end of the year amid fears over disruption to diesel supplies in particular.
Among other G7 countries, the US has banned Russian oil imports, while the EU is planning to ban seaborne Russian oil imports by the end of the year.
Ministers are aiming to have the price cap in place in time for the EU import ban, with details still being finalised.
The price of Brent crude rose slightly on Friday as traders anticipated potential production cuts as recession fears loom.
It came as the deputy chairman of Russia’s central bank admitted Russian banks had lost a combined 1.5 trillion roubles ($25bn) in the first half of the year as western sanctions shut the country out of large parts of the global financial system.
It marks the first time Moscow has disclosed figures for its banking sector since the invasion of Ukraine.
Russia’s financial system has been a key target of sanctions as the West tries to stymie the Kremlin’s war chest.
Dmitry Tulin, first deputy chairman, said around two-thirds of the losses came from foreign currency operations as lenders were blocked from trading in dollars, euros and other currencies.
He told business newspaper RBC that the losses were concentrated among Russia’s “systemically important” banks, which are the largest and have higher capital adequacy requirements.
Mr Tulin insisted the central bank did not expect a repeat of the 2014-17 banking crisis, when the regulator had to bail out several lenders.
In June, Russia defaulted on its foreign debt for the first time since the Bolshevik Revolution in 1918 after the US blocked access to $600m of funds in Wall Street banks, leaving it unable to make repayments.
The central bank’s assets have been frozen, blocking access to more foreign reserves, while many Russian lenders have been excluded from the Swift international payments system.
The UK has also frozen Russia out of its financial system, alongside its move to phase out all energy imports from the country.
Mr Tulin said it had become “more and more problematic” for Russian lenders to make payments in “toxic” currencies even when they were not directly targeted by sanctions.