Australian Prime Minister Malcolm Turnbull has declared his visit to Washington DC a success after ‘frank and productive meetings’ with US President Donald Trump, military leaders, business executives and more than 40 state governors.

Mr Turnbull and his wife Lucy departed the US for Canberra on Saturday (Sunday morning AEDT).

They gave Mr Trump and first lady Melania RM Williams boots as gifts during Friday’s four-hour visit at the White House.

Ms Turnbull also gave Ms Trump a scarf made by a small business located in the Wentworth electorate.

‘This has been a very, very valuable visit,’ Mr Turnbull told reporters on Saturday before leaving for Maryland’s Andrews Air Force Base and the long flight home.

‘Our goal was to broaden and deepen our enduring relationship with the US, our great alliance, build on 100 years of mateship for 100 more.’

Mr Trump told Friday’s White House press conference he would ‘love’ the Australian Navy to join US freedom of navigation patrols in the South China Sea.

A day later Mr Turnbull declined to rule out granting Mr Trump’s wish, a move that would anger China.

‘Australia, as you know, defends the right of freedom of navigation and overflight throughout the world but we do not want to speculate on operational matters,’ Mr Turnbull said.

Mr Turnbull said he did make a compelling case to Mr Trump that Australia should not be hit by any hefty tariffs on steel and aluminium imports into the US.

Mr Trump reportedly wants to introduce a global tariff of 24 per cent on steel and 10 per cent on aluminium imports.

‘We believe we have made a very compelling case, but obviously the administration has to finalise its decision in this area,’ Mr Turnbull said.

The prime minister’s last stop on his four-day visit to Washington DC was accompanying NSW Premier Gladys Berejiklian, Queensland Premier Annastacia Palaszczuk, Victorian Premier Daniel Andrews, West Australian Premier Mark McGowan, ACT Chief Minister Andrew Barr and Northern Territory Chief Minister Michael Gunner to the National Governors Association Winter Meetings.

It is the annual meeting for the governors of US states.

The prime minister told the governors America’s leadership in the world was in the interest of both nations.

The Australian premiers and chief ministers also took turns addressing the large ballroom and promoting their states and territories.