Russia’s foreign currency payment rating has been downgraded after Moscow used rubles to make a dollar-denominated debt payment earlier in the week, a move that rating agency S&P Global said casts doubt on Russia’s ability or willingness to honor its obligations to foreign debtholders. S&P Global on Saturday cut Russia’s rating to “selective default,” saying in a statement that it understood that Russia had made coupon and principal payments on dollar-denominated Eurobonds on Monday. “We currently don’t expect that investors will be able to convert those ruble payments into dollars equivalent to the originally due amounts, or that the government will convert those payments within a 30-day grace period,” the agency said. The agency added that it believes that sanctions against Russia over its invasion of Ukraine will be tightened again shortly, a move that it said was likely to impede Moscow’s willingness or “technical abilities” to meet the terms …