WASHINGTON—The U.S. Internal Revenue Service has suspended information exchanges with Russia’s tax authorities in a bid to hamper Moscow’s ability to collect taxes and fund its war against Ukraine, the Treasury Department told Reuters on Tuesday. Under a 30-year-old tax treaty, the IRS and Russia’s Federal Tax Service have shared information to aid domestic tax collections and enforcement of tax laws in both countries. The IRS can request information about U.S. taxpayers from Russian authorities and vice-versa. The Treasury said it has not shared any tax information with Russian authorities since Russia’s invasion of Ukraine began on Feb. 24, but the action disclosed on Tuesday formalizes the suspension. “This ensures that the United States is not providing any information that could contribute to the enrichment of the Russian government through increased tax collections or facilitating in any way the persecution of Russian dissidents or the targeting of Ukrainian citizens or …