He then admitted to the Russians that he felt he had relieved that "pressure" after he dismissed director Comey.
According to notes taken at that meeting Trump then went on to disparage Comey saying...
“I just fired the head of the F.B.I. He was crazy, a real nut job,”
In addition Trump also told the Russians that he was not under investigation for what that's worth.
The White House did not refute the Times’ report.
If, at this point, anyone questions as to why Comey was fired Trump has just erased any doubt.
Any case for obstruction of justice against Trump just got infinity easier.