Matthew Bryza, diplomat, former adviser to the U.S. Secretary of State, former director for Europe and Eurasia at the U.S. National Security Council, stated this on Espreso TV."Ultimately, only one thing will force Putin to end the war - when Russia runs out of money. The sanctions that President Trump imposed against Lukoil and Rosneft were a sharp turn in U.S. policy. Previously, Washington adhered to an approach where Russian oil had to remain on world markets to prevent excessive price increases and their possible impact on the American economy and elections. The previous policy stipulated that Russian oil could only be bought at a price below a set limit - initially it was $60 per barrel," Bryza explained.He explained that the new American sanctions against the supply of Russian oil to world markets significantly affected Russia's capabilities, as Russia is rapidly spending its reserve funds."Now President Trump is pursuing a completely different policy aimed at reducing the supply of Russian oil to world markets, which effectively deprives the Kremlin of key sources of foreign exchange earnings. This deals a serious blow to the Russian economy, especially given that the country is rapidly spending its reserve funds. Despite Moscow's attempts to rebuild the economy on a war footing, there will come a moment when financial resources simply run out, and it will become impossible to continue the war," he added.According to the diplomat, Putin seeks to continue the war, and only economic pressure can force him to stop it."It is worth remembering that military production is one of the least economically efficient forms of investment. Weapons are created for use and are often destroyed on the battlefield, so they do not provide a lasting multiplier effect for the economy. I believe that economic pressure will eventually force Putin to end the war. He seeks to continue fighting for as long as possible, hoping that Ukraine will be exhausted first and that European support will disappear before Russia's financial resources run out," he concluded.Sanctions against the Russian FederationOn October 22, the U.S. Treasury Department imposed sanctions against Russia's two largest oil companies, Rosneft and Lukoil, due to Moscow's unwillingness to end the war in Ukraine. It is noted that the restrictions are aimed at undermining Russia's ability to generate profits to continue the war, primarily through the energy sector.After the introduction of new U.S. sanctions, seaborne supplies of Russian crude oil fell to their lowest level since January 2024.On November 3, state-owned companies Sinopec and PetroChina Co. suspended purchases of some Russian cargoes. Smaller private refineries also joined the boycott.