Media playback is unsupported on your device Media caption Why has Australia's PM been invited for a state dinner at the White House?

President Donald Trump has welcomed Australian PM Scott Morrison on a week-long visit to the US which includes a state dinner at the White House.

The pair met at the White House where Mr Morrison was greeted with a military band and a 19-gun salute.

The two are close politically and have lavished praise on one another.

Mr Morrison is just the second world leader to be given a state dinner by President Trump after France's Emmanuel Macron.

Mr Morrison and Mr Trump both heralded the decades-long relationship between their two countries as the Australian PM arrived at the White House.

Image copyright Alex Wong/Getty Images Image caption The two men and their wives met outside the White House

"Australians and Americans understand each other like few other people," Mr Morrison said. "We have done what true friends do: stick by each other."

What's their relationship like?

The two conservative politicians spent time together at the G20 Summit in Osaka, Japan, in June as well as earlier that month at the at D-Day event in Portsmouth, England, leading some to speculate about a budding "bromance".

During a dinner with Mr Morrison in Osaka, Mr Trump praised his counterpart, and boasted that he had predicted his victory at the ballot box.

"He didn't surprise me but he surprised a lot of other people. See, I knew him. So I said he's going to do very well and he did," Mr Trump told US and Australian officials.

Mr Trump has frequently lavished praise on Mr Morrison - who became prime minister in August 2018 and won a surprise re-election in May - as well as his controversial immigration positions.

Mr Morrison has in turn praised the American president as "a strong leader who says what he's going to do and then goes and does it".

"I get on very well with him," he said in a recent interview, adding that they have a "straight-up relationship".

What will Morrison be doing in the US?

The Australian prime minister nicknamed "ScoMo" will visit the headquarters of Nasa, the US space agency, and will travel to Chicago to meet tech entrepreneurs during his visit from 19-27 September.

After a joint press conference on Friday, Mr Morrison and his wife Jenny will be hosted at the state dinner.

On the menu is Jerusalem artichoke ravioli, Dover sole with fennel mousseline and apple tart with calvados ice-cream for dessert.

The events are rare, largely owing to the months of planning that go into them. They are designed to showcase America's closest diplomatic relationships with foreign allies.

Media playback is unsupported on your device Media caption President Macron arrives for a state dinner

On Sunday, Mr Morrison travels to Wapakoneta, Ohio, to tour a "new, Australian-owned manufacturing facility" with President Trump, the White House said in a statement.

Two days later, Mr Morrison will travel to New York City for the UN General Assembly meetings to deliver an address that will cover "the protection of the oceans and preventing terrorist use of the internet", his office said.

How significant is this to Australia?

Beyond the bromance, there's plenty at stake. Australia has typically shown steadfast loyalty towards the US, its key strategic ally - a point which Mr Morrison emphasised before his trip.

"We are an alliance partner that the United States knows they can rely on, a partner that pulls their weight in the alliance," he told parliament this week.

It's particularly relevant now, experts say, as Australia balances the primacy of its US alliance against its crucial relationship with China, its largest trading partner.

Australia remains economically reliant on China but is openly debating its influence on local society, amid concerns about security and freedom of speech.

The Trump-Morrison discussions are likely to be watched for any mention of Beijing and the US-China trade war, as well as other economic and security matters.