Fresh reporting raises new questions about President Donald Trump¡¯s possible ties to Russia and emphasizes the need to ensure that special counsel Robert Mueller¡¯s investigation reaches its conclusion without interference, Senate Democrats said Sunday.

The New York Times reported Friday that the FBI had opened a probe in 2017 to determine whether the president had worked, knowingly or unknowingly, on behalf of Russia and against U.S. national interests. On Saturday, a Washington Post story said Trump went to great lengths to hide details of his discussions with Russian President Vladimir Putin.

The reports build on previous questions about Trump¡¯s connections with Russia that need to be investigated, Democratic Sen. Tim Kaine of Virginia said on NBC¡¯s ¡°Meet the Press.¡± Mueller¡¯s probe into Russian interference in the 2016 presidential election must be allowed to finish to provide the answers, he said.