WASHINGTON – Donald Trump’s National Security Adviser Michael Flynn resigned on Monday night in what appears to be a major setback for US president.

The White House confirmed the resignation announcing that Trump had named Lt. General Joseph Keith Kellogg, Jr. as acting national security adviser.

Mr Flynn is alleged to have discussed US sanctions with the Russian ambassador before Mr Trump entered Oval office. He is said to have misled officials about his the conversation.

In his resignation letter, Flynn claimed he had mistakenly misled vice-president Mike Pence and other Trump officials about the nature of phone calls in December to the Russian ambassador, Sergei Kisilyak.

Flynn’s resignation letter

When intelligence leaks about the communications began appearing last month, Pence and other White House officials insisted the contact had involved only an exchange of Christmas greetings and arrangements for a future phone conversation between Trump and Vladimir Putin.

‘Unfortunately, because of the fast pace of events, I inadvertently briefed the Vice President Elect and others with incomplete information regarding my phone calls with the Russian Ambassador. I have sincerely apologised to the President and the Vice President, and they have accepted my apology,’ Flynn said in his resignation letter.

It is relevant to mention that Flynn had accepted the prestigious post in November following the unexpected landslide victory of Donald Trump and he remained ni office for approximately 25 days.

On the other hand, former secretary of state Hillary Clinton took to Twitter to express her views regarding the latest resignation.