Scott Morrison grins and bears it as Donald Trump goes rogue

Washington: Scott Morrison would have prepared for many scenarios in the lead-up to his historic one-on-one Oval Office meeting with Donald Trump.

But not even a prime minister with extra sensory perception could have seen this coming: a threat to dump thousands of potential terrorists on the border of some of America's closest allies.

Past US presidents would invite the media into the start of their meetings with foreign leaders to capture some handshake pictures and record them saying a few introductory remarks. Then the press would be quickly booted out.

Under Trump, those banal photo opportunities have morphed into something far more captivating: freewheeling press conferences in which he spars with journalists and waxes lyrical about whatever is on his mind.

And so it was on Friday local time (Saturday AEST) as Trump answered questions for half an hour - musing on everything from his trade war with China to a potential war with Iran to Canadian Prime Minister Justin Trudeau's "brownface" scandal.

Sitting beside him was the Australian Prime Minister, looking like a hostage on happy pills. At times Morrison appeared bemused, at others amused - as if he could hardly believe this surreal moment was actually happening.

The room was electric with the possibility that Trump's mood could change at any minute, that anything was possible - a sensation Trump encouraged. Volatility is the juice in his machine.

"It could take place in one minute," Trump said when asked when he was considering a military strike on Iran. "I could do it here in front of you."

He added: "We all hope, and Scott hopes, we all pray that we never have to use nuclear."

Nothing gets the blood pumping quite like a US president casually floating the prospect of nuclear war.

Jenny Morrison and Prime Minister Scott Morrison meet with US President Donald Trump and Melania Trump.Credit: Alex Ellinghausen

The most stunning moment came when Trump, without any prompting, raised the subject of the foreign fighters captured during America's war with the Islamic State (or ISIS).

"Now we have thousands of former ISIS fighters who are prisoners of war," Trump said.

"At some point I'm going to say 'You have to take them back or I'm going to set them loose at your border'.

"They came out of Germany, they came out of France. We did them a big favour."

In case anyone missed the message he repeated it: "The United States is not going to pay the costs of thousands and thousands of prisoners in Guantanamo Bay or some place else. We won't do it."

Mercifully for Morrison, Trump's anger was focused on Europe. The President hasn't yet suggested repatriating captured IS fighters to Australia without clearing it with us first.

It was an altogether different President Trump than the one on display earlier that morning at an extravagant welcome ceremony outside the White House.

It was a gorgeous morning in Washington. Sun in the sky. A chill in the air. Dew on the green, green grass of the South Lawn. Military officers arranged in formation, and crowds waving flags.

The Trump we saw there was "Teleprompter Trump", content to read scripted remarks about the importance of the US-Australia alliance. He was stiff, contained - dare one say presidential?

Scott and Jenny Morrison were given an extravagant welcome ceremony outside the White House.Credit: Alex Ellinghausen

In the Oval Office - a room that looms large in political history but is remarkably small - we saw Trump unplugged.

He delighted in New York mayor Bill de Blasio's decision to drop out of the Democratic presidential primary contest. "His only asset was his height," Trump said.

Asked whether he was only concerned about trade with China or if he saw the country as a strategic threat, he said: "Obviously China is a threat to the world in a sense because they are building their military faster than anybody and frankly they are using US money.

"China wants to make a deal, I think we want to make a deal."

While flaunting his ability to inflict colossal damage on Iran, Trump boasted that he has not behaved like the warmonger Hillary Clinton and other Democrats predicted.

Bombing Iran, he said, was the "easiest thing I could do ... the thing that does show strength is actually a little restraint".

For the final question, Trump was asked how he would describe Morrison. "Titanium man," Trump instantly replied, an upgrade on George W Bush's description of John Howard as a "man of steel".

Morrison looked delighted - and more than a little relieved it was all over.