Will US Sanctions On Russian Oil Slow The Kremlin's War On Ukraine?

Russian oil has been a prime cash source for the Kremlin's war in Ukraine. So will the newly announced US sanctions against Russian energy giants LUKoil and Rosneft have an effect on Vladimir Putin's war chest? US President Donald Trump, announcing his first set of sanctions on Russia since his reelection, says both companies' US assets will be frozen. Also, American companies will be barred from doing business with them and foreign financial institutions will also be targeted. Does that mean major Russian oil importers like India will also feel the bite?