German Chancellor Angela Merkel has dealt with so many Australian prime ministers since 2013 she uses a cheat sheet with a picture.

She met with Prime Minister Scott Morrison at the G20 in Argentina on Saturday local time and her briefing note included a picture of him.

Ms Merkel has been leading Germany since 2005, which covers part of John Howard's reign, plus that of Kevin Rudd, Julia Gillard, Mr Rudd again, Tony Abbott, Malcolm Turnbull and now Mr Morrison.

The meeting came a day after Mr Morrison's first meeting with US President Donald Trump, who quizzed him about what happened to Mr Turnbull.

AAP