Washington, Feb 16 (IANS): US Senate Republicans are expressing growing concerns about the relationship between President Donald Trump's administration and Russia, the media reported.

"Everybody is unnerved by what they read, but (they're) not going to make decisions based on headlines," said South Carolina Senator Lindsey Graham.

Senate Foreign Relations Committee Chairman Bob Corker acknowledged that calls for a wide-ranging investigation have "gained momentum over the last 48 hours", The Hill magazine reported.

The administration's relationship with Russia drew renewed attention on Monday after the resignation of Michael Flynn as President Trump's National Security Adviser.

Flynn left his post after reports that he held multiple phone calls with Russia's ambassador to the US about sanctions on Moscow before Trump took office.

While the White House said Flynn was ousted because of a lack of trust -- he misled Vice President Pence and others about those discussions -- the conversations themselves raised new questions about ties between Team Trump and Moscow, worrying Republicans in the Senate.

Senate Majority Leader Mitch McConnell has directed the Senate Intelligence Committee to look into Russia's role in influencing the US presidential election, a stance supported by his conference.

Democrats are also asking that the findings of the Senate Intelligence Committee's investigation be made public.