title: Key U.S. Republican: Flynn situation adds 'momentum' to Russia probe
text: WASHINGTON (Reuters) - A senior U.S. Senate Republican said on Tuesday that the resignation of President Donald Trump’s national security adviser, Michael Flynn, would “add momentum” to congressional investigation of Russia’s involvement in the 2016 U.S. election. Senator Bob Corker, the Republican chairman of the Senate Foreign Relations Committee, also told reporters Flynn may need to testify at a congressional hearing on the matter. 