President-elect Donald Trump has put his own twist on sending out new year wishes, including a message to his "many enemies".

The Republican, who has been questioned over his prolific Twitter use and online spats, sent out a new year tweet that demonstrated he has no plans to tone down his use of social media.

Trump wrote in a tweet: "Happy New Year to all, including to my many enemies and those who have fought me and lost so badly they just don't know what to do. Love!"

It is the latest in a series of tweets that have prompted questions over his unique style and whether he will continue to be so vociferous on social media following his inauguration on 20 January.

Most recently, the Republican spoke out in support of Russian president Vladimir Putin's decision not to react to the expelling of Russian diplomats from the US and sanctions imposed by Barack Obama over alleged hacking of the US election, and sent a tweet suggesting China should "keep" the drone it seized from the US Navy.

Trump has tweeted: "Great move on delay (by V. Putin) - I always knew he was very smart!", in a direct contrast to the decision taken by the president, who he had criticised several days earlier for reportedly failing to make Trump's presidential transition smooth.

"Doing my best to disregard the many inflammatory President O statements and roadblocks. Thought it was going to be a smooth transition - NOT!" Trump wrote, continuing the ongoing war of words between Obama's transition team and the White House.