Later during the evening, the Washington Post announced that President Trump had ignored a warning from National Security written in bold caps. The message, intended for the President had been prior to the Putin phone call, not to bring up the congratulations.
After the Post article broke, John Kelly, Chief of Staff has gone on the warpath due to the purported lack of the homeland security information and warning.
The issue surrounding Trump and Russia has been complicated due to the entire Russia election controversy, including the 2016 elections meddling and recent revelations of attacks on British soil.