WASHINGTON (DPA) - The odd nature of President Donald Trump's relationship with North Korea came to the fore on Sunday (Nov 17) as he seemed to defend his domestic rival, Mr Joe Biden, who was called a "rabid dog" by state-run media in the reclusive Communist state.

However, even Mr Trump's nominal defence was laced with barbs of his own.

"Mr Chairman, Joe Biden may be Sleepy and Very Slow, but he is not a 'rabid dog'. He is actually somewhat better than that," Mr Trump said on Twitter, rehashing nicknames for his rival.

The President went on to make a push for diplomacy with Pyongyang, as the track that was opened in 2018 with a summit between North Korean leader Kim Jong Un and Mr Trump has stalled, with no progress on denuclearisation.

There is concern that without headway before the end of the year, Pyongyang may start to act more aggressively.

"I am the only one who can get you where you have to be. You should act quickly, get the deal done. See you soon!" Mr Trump said to Mr Kim.

Mr Trump's rivalry with Mr Biden, the Democratic front-runner, has been at the centre of an ongoing impeachment inquiry, amid concerns he wanted Ukraine to dig up dirt on his adversary.

Mr Biden said he saw the attacks against him by North Korea as a "badge of honour".

State media said "rapid dogs" like Mr Biden "must be beaten to death with a stick, before it is too late".

Mr Trump traded insults with North Korea when he first came to office, vowing to bring down "fire and fury" and calling Mr Kim "rocket man", while North Korea branded him a "dotard".