Khabib Nurmagomedov appeared to react to Conor McGregor's retirement with a cryptic social media post on Tuesday.

McGregor had hinted at a return to the octagon once he had served his six-month ban for the brawl after his fight with Nurmagomedov at UFC 229 in October – which the Russian won - but announced his shock decision on Monday.

"Hey guys quick announcement: I've decided to retire from the sport formally known as 'Mixed Martial Art' today," he wrote on Twitter.

The former two-weight UFC champion has a long-standing rivalry with Nurmagomedov, but the Russian did not appear to be concerned as their feud seemingly reached its conclusion.

Uploading an image with the lightweight belt he defended against McGregor, Nurmagomedov posted a short message on his own Twitter page.

"There can be only one king in the jungle," he wrote.

Nurmagomedov is serving a nine-month ban for his role in the brawl between his team and McGregor. His suspension is set to end at the start of July.