Donald Trump, the US President-elect, offered former military intelligence chief Michael Flynn the job of national security adviser as he began to build out his national security team on Thursday, according to a senior Trump official.

Retired Lt. Gen Flynn, who served as the director of the Defence Intelligence Agency, has advised Mr Trump on national security issues for months. 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.

The official wouldn't say whether Lt. Gen Flynn had accepted the job, which left open the possibility that the arrangement was not finalised.

Lt. Gen Flynn, who turns 58 in December, built a reputation in the Army as an astute intelligence professional and a straight talker. He retired in 2014 and has been a fierce critic of President Barack Obama's White House and Pentagon, taking issue with the administration's approach to global affairs and fighting Islamic State militants.