A senior Trump official confirmed on Thursday that Flynn had been offered the role of National Security Advisor.

It was, however, unclear whether the 57-year-old registered Democrat, who advised Trump on national security issues during his run for the White House, had accepted the influential role.

Asked if Flynn is expected to accept, a person familiar with the offer replied: "When the president of the United States asks you to serve, there is only one answer."

As national security adviser, he would work in the White House and have frequent access to the president. The post does not require Senate confirmation.

Outspoken adviser

Flynn, who was fired as head of the Defense Intelligence Agency by President Barack Obama in 2014, reportedly favors closer ties with Russia, as Trump himself has advocated.

He has also criticized the Obama administration for its policies in the Middle East and has been vocal about the threat from Islamist terrorism, arguing in a 2014 interview that the US was less safe from terrorism than before the September 11, 2001 attacks.

Flynn, who often introduced the reality TV star at campaign rallies, has also been censured for his pro-Trump tweets, and was forced to apologize after retweeting an anti-Semitic message.

As a foreign policy novice, Trump's appointments are being closely watched by US allies and adversaries alike.

The role of National Security Advisor was created during the Cold War. The position has been held by the likes of Henry Kissinger, Colin Powell and Condoleezza Rice, and is currently held by Susan Rice.

mm/kl (AP, dpa, Reuters)