Four Americans and the Aussie pilot were killed when the plane they were travelling aboard crashed into a DFO.

The American golfers were in the midst of a golf trip around Australia and were flying to King Island to play golf.

The chartered plane crashed shortly after taking off from Essendon Airport.

Trump said his thoughts and prayers were with the families those killed in the crash.

"First off I want to acknowledge the tragic plane crash that occurred in Australia that took the lives of five individuals, including four Americans," White House spokesman Sean Spicer, at the start of Tuesday's press conference, told reporters.

"The president's thoughts and prayers are with the families of the victims and the US embassy and consulate are ready to provide necessary and appropriate assistance."