Former prime minister John Howard was famously visiting Washington at the time of the 9/11 terrorist attacks and now Malcolm Turnbull has his own experience of a presidential lockdown while at The White House.

The US Secret Service swung into action during a press conference between President Donald Trump and Mr Turnbull after an incident at a security barrier.

A Secret Service agent rushes past reporters after the White House incident. Photo: AP

Australian and US reporters in the White House press briefing room were taken to a basement while authorities investigated the incident.

The Secret Service tweeted a female driver crashed her car into a security barrier of the White House complex, saying “no shots were fired during the vehicle incident near the White House”.

The woman was “immediately apprehended” and no law enforcement personnel were injured.

A spokesman for Mr Turnbull said the Australian Federal Police advised the crash had “no impact on the Prime Minister”.

The driver, who was not immediately named, is known to the Secret Service and is believed to have mental health issues. She is not thought to have intentionally targeted the President, law enforcement sources told CNN.

Mr Trump later thanked the secret service in a tweet for a job “well done”.

Thank you to the great men and women of the United States @SecretService for a job well done!

— Donald J. Trump (@realDonaldTrump) February 23, 2018

Mr Turnbull’s exit from the White House was delayed after spending most of the day in talks with Mr Trump, culminating in a joint press conference which saw the two leaders addressed the tricky issue of gun laws.

But there was little spruiking of Mr Howard’s signature policy from the current Liberal leader.

Mr Turnbull was asked if he spoke to Mr Trump about toughening gun laws, as Australia did after the Port Arthur massacre, but said he did not want to lecture America.

Despite his party’s oft-stated pride in Mr Howard’s big achievement, the Australian PM was careful not to the weigh into the fraught subject, declining to advise Mr Trump to follow a similar path.

“It’s a completely different context historically, legally and so forth,” Mr Turnbull said.

We are very satisfied with our laws, but we certainly don’t presume to provide policy or political advice on that matter here.

“You have an amendment to your Constitution which deals with gun ownership – we’ll focus on our own political arguments and debates and wish you wise deliberation in your own.”

Mr Trump, who has suggested arming teachers in response to the Florida shooting, said comparing Australia and America was impractical.

“They are very different countries with very different sets of problems,” he said.

“But I think we’re well on the way to solving that horrible problem that happens far too often in the United States.”

He again promoted his idea to train teachers who could be armed within schools, saying it was “very, very important that we have offensive capability as well as defensive capability”.

Friendship between nations affirmed

Earlier, with First Lady Melania Trump by his side, Mr Trump declared America’s relationship with Australia is “stronger than ever before” after greeting Mr Turnbull and wife Lucy on the South Lawn.

“The relationship we have with Australia is a terrific relationship and probably stronger now than ever before, maybe because of our relationship, our friendship,” Mr Trump said.

The Turnbulls and Trumps enjoy a quiet moment. Photo: The White House

“We’re working on trade deals, we’re working on military and protection and all of the things that you would think we would be discussing today.

“A lot of good things will come out of this visit.”

Mr Turnbull said it was the 100th anniversary of the World War I battle for Hamel in France where Australian and US forces first fought together.

“We have been fighting side-by-side in freedom’s cause ever since, 100 years of mateship and 100 more to come.”

The leaders were expected to discuss tough new sanctions Mr Trump announced against North Korea, trade, security in the Indo-Pacific and infrastructure investment.

Leaders show united front against North Korea

Standing side by side at separate podiums at a joint press conference, Mr Trump said the world might be in for a “very unfortunate day” if America’s latest sanctions on North Korea do not curb the rogue regime’s nuclear missile program.

Mr Trump and Mr Turnbull put on mostly a united agreeing on continuing pressure on North Korea with sanctions, “merit based” immigration and dealings with China and Syria.

However, they did differ on the Trans-Pacific Partnership and gun control.

“We’ll have to see,” said Mr Trump, when asked if all options are still on the table if the sanctions don’t work.

He did not rule out a “very rough day” with a military response toward North Korea.

“Maybe very unfortunate for the world,” the president said.

Mr Trump also announced the US would name a new combat ship the USS Canberra.

-With ABC/AAP