Donald Trump's 17-day break 'not a vacation', US President insists

'Meetings and calls,' President tells his Twitter followers

President Trump alights Air Force One with his grandchildren after arriving at Morristown Municipal Airport (AP)

Donald Trump has insisted he is not on holiday as he takes a 17-day break from the White House.

Mr Trump tweeted on Friday night that he was away, at his Bedminster, New Jersey golf club, because the nation's most famous residence was undergoing "long-planned construction".

"This is not a vacation—meetings and calls!" he said.

The entire West Wing staff has had to relocate while a 27-year-old heating and cooling system is replaced, it was reported.

White House officials had billed the trip as a "working vacation", but analysts said respite might be hard to come by because of the probe into alleged links between Mr Trump's campaign and Russia.

"I think he will be troubled. If not, then I hope some of his staff take the opportunity to bring him up to speed on the gravity of the situation," Christina Greer, associate professor of political science at Fordham University in New York, told The Independent.

Shortly after winning the presidency Mr Trump declared that "I don't think we'll be very big on vacations" because "there's just so much to be done".

However, he has spent many weekends at his resorts in Florida and Virginia, prompting criticism from his opponents.

He arrived in Bedminster on Friday, and on Saturday was seen chatting with wedding guests after stopping his golf cart to speak with them.

In video posted by WPVI-TV in Philadelphia, the Republican President got out of his cart and asked the group if they were having a good time, then paused to take a selfie with one of them before he went inside the club.

The President also took to Twitter to praise his Attorney General, Jeff Sessions, for taking a public stance against the leaks by administration staff that have plagued the Trump premiership.

He said: "After many years of LEAKS going on in Washington, it is great to see the A.G. taking action! For National Security, the tougher the better!"

Mr Trump had previously lashed out at Mr Sessions, a staunch supporter, over his decision to recuse himself from the Russia investigation.

Press freedom advocates said they feared Mr Sessions' plan to review the Justice Deparment's use of subpoenas, and potentially force reporters to hand over details of their sources, represented "a dangerous escalation of the administration’s war against the press".

Additional reporting by agencies