STORY: Group of Seven finance ministers agreed on Friday to impose a price cap on Russian oil.

They aim to slash revenues for Moscow’s war in Ukraine - while keeping crude flowing to avoid price spikes.

The price cap per barrel is still being discussed.

In a statement, U.S. Treasury Secretary Janet Yellen said the cap would put downward pressure on global energy prices, quote, "while denying Putin revenue to fund his brutal war in Ukraine.”

The aim is to introduce it starting in December, timed with planned EU sanctions on Russian oil.

The ministers are seeking a broader coalition of countries to buy Russian oil products at or below the price cap.

But some G7 officials fear it will fail without participation of other major economies such as China and India.

Which have sharply increased their purchases of Russian crude since Moscow launched its invasion in February.

But others say China and India have expressed interest in buying Russian oil at an even lower price in line with the cap.

Enforcing the cap would rely heavily on denying London-brokered shipping insurance, which covers about 95% of the world's tanker fleet.

It would also mean denying finance to cargoes priced above the cap.

But analysts say that alternatives can be found to circumvent the cap and market forces could render it ineffective.