EDINBURGH, United Kingdom - Prime Minister Justin Trudeau marked Canada's 150th birthday with the Queen by giving her the Canadian flag that flew on the Peace Tower on Canada Day.

On a day-long stop in Edinburgh, Trudeau met with the Queen for a private audience at her official Scottish residence where he presented her with the Maple Leaf raised last weekend.

The meeting was arranged to mark Canada's sesquicentennial since the 91-year-old Queen is no longer able to travel as far as Canada.

Prince Charles and the Duchess of Cornwall had attended Canada Day events in her place.

While Trudeau was in the palace, some protesters approached the gates holding placards calling for an end to the tar sands and to grant Indigenous rights.

It was a taste of what is to come for Trudeau at the upcoming G-20 summit in Germany where tens of thousands of anti-globalization protesters have already started to descend on the northern port city of Hamburg.

Fireworks are also expected inside the G-20 meeting as leaders clash over trade, climate change and international security.