New York, United States |Donald Trump's transition to power has every appearance of a family affair, fuelling concerns about conflicts of interest and a lack of experience in the future Republican president's inner circle.

Official snaps of the president-elect's first meeting with a foreign leader triggered a torrent of criticism: they show Ivanka Trump sitting in on the talks with Japan's Shinzo Abe, while she and her businessman husband Jared Kushner can be seen chatting and laughing with the prime minister's delegation at Trump Tower.

"Conflict of interest is an understatement," tweeted Matt Ortega, a member of the digital team for Trump's defeated Democratic rival Hillary Clinton.

"OMGOMGOMGOMGOMG," reacted the left-wing magazine Mother Jones.

While he insists Ivanka, Donald Jr and Eric will hold no formal posts in his administration, the billionaire president-elect has since his November 8 election given Americans good reason to believe his adult children will continue to play an important role at his side.

And the seemingly pivotal role being played by Kushner, Trump's businessman son-in-law, in assembling the Republican's administration is already drawing scrutiny after he was reported this week to be pulling strings in the process.

It was reported -- and denied by Trump -- that inquiries had been made about top-secret clearance for Kushner to be able to join daily presidential briefings.

The New York Times reported -- citing anonymous sources -- that Kushner had reached out to a lawyer about the possibility of joining his father-in-law's administration, without violating anti-nepotism laws.

For mixing family and politics is not that simple in the United States.

A 1967 law -- adopted after John F Kennedy, as president-elect, named his brother Bobby as attorney general -- bars any blood relative or in-law of the US president from holding paid employment for a federal agency.

But the legislation appears to be a lot less clear when it comes to White House advisor positions.

- Too many risks of conflict -Presidential politics as a family affair is nothing new in America, says Sam Abrams, a professor of political science at Sarah Lawrence College in New York. 

From Eleanor Roosevelt to Michelle Obama, and of course the Kennedys, Bushes and Clintons, the wives and children of US heads of state have often played a key -- if informal -- role, without raising red flags over nepotism.

But for Daniel DiSalvo, an expert at the City College of New York-CUNY, Trump throws several challenging new ingredients into the mix: "The character of Trump's business -- his name is one of the main assets on his buildings, golf courses -- the scale of his fortune and the number of adult children" involved in his businesses.

"That's the issue: how much of this is going to create conflict of interest issues," said DiSalvo.

While Trump says his children -- who all sit on his transition team -- will play no official administration role, he does plan to have them continue to run his businesses, which ethics watchdogs warn would pose too many potential risks of conflict.

Ivanka Trump's very first televised appearance at the president-elect's side -- in a prime-time interview -- triggered a mini-scandal after her fashion company sent out a message promoting the $10,000 gold bracelet she wore on air.

Abrams believes Trump is committing a mistake by allowing his family to figure so prominently -- before he has even taken office, and before he has finished building a qualified team to surround him.

"It's normal to involve family," Abrams said. But he also believes that to rely that heavily on immediate family is "offputting for a lot of people."

Experts expressed surprise that Trump did not request a State Department briefing before his meeting with the leader of one of Washington's closest allies -- but had Ivanka and Kushner in the room.

Seeking counsel might have appeared all the more pertinent since Trump had alarmed Tokyo policymakers during his campaign by musing about pulling the thousands of US troops from the region and suggesting that officially pacifist Japan may need nuclear weapons.

"When you are going to be meeting with, a trusted ally of the US, you should be talking to your experts... and not instead going to Jared to say, 'What do you think about this?'" Abrams said. Shinzo Abe

In the tense climate following Trump's election, on the back of a divisive populist campaign, he said, "it's not helping the American people to feel better about themselves."