Donald Trump has launched a series of tweets targeting the treatment of his daughter Ivanka, the “failing New York Times”, Islamic refugees and claims the cost of his Mexican wall would come “WAY DOWN” when he gets involved in negotiations, all while hosting the Japanese Prime Minister at his privately-owned resort at the weekend.

But the US President, who also played a round of golf with Shinzo Abe at his course in Jupiter, Florida, did not say how he would bring down the cost of the wall.

Reuters on Thursday published details of an internal report by the Department of Homeland Security that estimated the price of a wall along the entire border at $US21.6 billion ($A28.1 billion).

During his presidential campaign, Mr Trump had cited a $US12 billion figure.

“I am reading that the great border WALL will cost more than the government originally thought, but I have not gotten involved in the … design or negotiations yet,” Trump tweeted.

“When I do, just like with the F-35 FighterJet or the Air Force One Program, price will come WAY DOWN!”

Mr Trump took time out of his diplomatic duties to remind his followers that he disagreed with the decision by department story Nordstrom to drop daughter Ivanka’s clothing and accessories from its stores.

I am so proud of my daughter Ivanka. To be abused and treated so badly by the media, and to still hold her head so high, is truly wonderful!

— Donald J. Trump (@realDonaldTrump) February 11, 2017

Mr Trump also tweeted on Saturday about another aspect of his immigration policy – the legal battle over the presidential order banning entry to the United States by refugees and citizens of seven Muslim-majority countries.

Our legal system is broken! "77% of refugees allowed into U.S. since travel reprieve hail from seven suspect countries." (WT) SO DANGEROUS!

— Donald J. Trump (@realDonaldTrump) February 11, 2017

The tweet was in apparent reaction to a Washington Times story saying 77 per cent of the 1100 refugees who have entered the United States since February 3 are from the countries covered by Mr Trump’s ban.

A federal judge in Seattle blocked Mr Trump’s executive order on February 3, lifting the ban while litigation proceeds. The President has been steadily critical of the ruling from Seattle and a subsequent appeals court ruling upholding it.

And finally, the President turned his attention to The New York Times:

The failing @nytimes does major FAKE NEWS China story saying "Mr.Xi has not spoken to Mr. Trump since Nov.14." We spoke at length yesterday!

— Donald J. Trump (@realDonaldTrump) February 10, 2017

Mr Abe and Mr Trump stayed at Mar-a-Lago, Mr Trump’s personal resort, after arriving in Palm Beach, Florida, on Friday evening.

After arriving at the Trump National Jupiter Golf Club & Spa, the pool of White House reporters were brought to a room in which the windows and doors were covered with a black plastic that prevented them from seeing outside.

Photographers were told not to take pictures on the grounds of the “private club”.

Mr Trump’s two-day meeting with Mr Abe was a first glimpse of how the New York real estate tycoon might conduct diplomacy during his four-year term.

Master dealmaker

Mr Trump, who took office on January 20, said in late January that his administration had been able to cut $US600 million from a deal to buy about 90 F-35 Joint Strike Fighters from Lockheed Martin.

Defence analysts and sources downplayed news of those cuts, saying the discount hailed by Mr Trump was in line with what had been flagged by Lockheed for months.

Mr Trump has vowed to make Mexico reimburse the United States for its cost but Mexico has repeatedly said it will not do so.

– with AAP