Failure to agree on a price cap for Russian oil will push international prices higher, a U.S. government official has warned, adding that the cap would need to be accompanied by sanction exemptions. In a report quoting the unnamed official, Reuters wrote that the idea of the price cap was to set a price for Russian oil that covers the marginal costs of its production as a way of motivating Russia to continue exporting that oil, even at much lower than international prices. Failure to do so means that sanctions on Russian crude oil will significantly…