US Secretary of State Marco Rubio said the Russian oil that China is buying is being refined by Beijing, and that refined oil is then sold into the global marketplace. "Well, if you look at the oil that's going to China and being refined, a lot of that is then being sold back into Europe. Europe's also buying natural gas still. Now, there are countries trying to wean themselves off it, but there's more Europe can do with regard to their own sanctions," Rubio said in an interview with Fox Business on Sunday.

He was responding to a question on whether Europe is still buying Russian oil. To a follow-up question on whether sanctions are being contemplated against Europe for continuing to buy oil and gas from Russia, Rubio said: "Well, I don't know about (sanctions) on Europe directly, obviously, but certainly there are implications to secondary sanctions.

"If you put secondary sanctions on a country ' let's say you were to go after the oil sales of Russian oil to China ' well, China just refines that oil. That oil is then sold into the global marketplace, and anyone who's buying that oil would be paying more for it or, if it doesn't exist, would have to find an alternative source for it.