Top Democratic and GOP leaders of the House Foreign Affairs Committee have called on President Donald Trump to investigate the poisoning of Russian opposition leader Alexei Navalny.In a bipartisan letter  sent to Trump on Monday, Representative Eliot Engel, the Democratic committee chairman from New York, and Republican Michael McCaul, the committee’s ranking member from Texas, urged the Trump administration to launch an investigation into the attack, saying sanctions against Moscow may be necessary.Navalny, a prominent opponent of President Vladimir Putin, fell ill on August 20 during a domestic flight in Russia. He was transferred to a hospital in Germany for treatment. The German government said on September 2 that toxicology results showed the 44-year old was poisoned with a Soviet-style Novichok  nerve agent.Suspicion surrounding the poisoning quickly mounted against the Russian government, which has used similar methods against critics of the state in the past. Most recently, the Kremlin was found to have used the same chemical weapon against an ex-Soviet spy in Britain in 2018. Navalny, who has been hospitalized in Berlin for several weeks, was taken out of a medically induced coma on Monday.In a statement issued Monday, Berlin’s Charité hospital said Navalny’s condition has continued to improve, but that it was too early to gauge the potential long-term effects of the severe poisoning.The Kremlin has denied any involvement in the poisoning and dismissed any accusations of a crime, saying there is no evidence to support a full-fledged criminal investigation into the case.On Tuesday, representatives of the G-7 condemned the “confirmed poisoning” of Navalny, according to a statement released by the U.S. State Department.”We, the G-7 foreign ministers of Canada, France, Germany, Italy, Japan, the United Kingdom and the United States of America and the High Representative of the European Union, are united in condemning, in the strongest possible terms, the confirmed poisoning of Alexei Navalny,” said the statement. White House spokeswoman Kayleigh McEnany said last week that the U.S. will be working with the international community to determine whether monetary sanctions should be levied against Russia.Lawmakers also called for the U.S. to demand that Russia cooperate with an international investigation by the Organization for the Prohibition of Chemical Weapons to bring the perpetrators to justice.“Those responsible for this despicable attack must be held accountable, and Russian President Vladimir Putin must know that he and his cronies will not be allowed to violate international law with impunity,” Engel and McCaul wrote in their letter to the president.