(CNN) Solemn ceremonies took place around the world Sunday to mark 100 years to the day since the Armistice that saw the end of World War I.

Members of the public, military veterans, world leaders and royals took part in memorials around the globe to remember the 8.5 million people who gave their lives between 1914 and 1918.

French President Emmanuel Macron led the international Armistice Day commemorations Sunday morning by the Tomb of the Unknown Soldier, which lies at the foot of the Arc de Triomphe monument in Paris.

Moroccan King Mohammed VI, US first lady Melania Trump, US President Donald Trump, German Chancellor Angela Merkel, French President Emmanuel Macron and his wife Brigitte attend a ceremony at the Arc de Triomphe in Paris.

"Patriotism is the exact opposite of nationalism," he said through a translator. "Nationalism is a betrayal of patriotism. By saying our interests first, who cares about the others, we erase what a nation holds dearest, what gives it life, what makes it great and what is essential: its moral values.

"I know there are old demons which are coming back to the surface. They are ready to wreak chaos and death," he said. "History sometimes threatens to take its sinister course once again."

US President Donald Trump and first lady Melania Trump were among those in Paris for the commemorations, which coincide with Veterans Day in the United States. Some 117,000 American military personnel died in World War I.

Trump's arrival wasn't as smooth as expected, being disrupted by a topless protester who ran towards the US President's motorcade as it was approaching the Arc de Triomphe. The woman, who had the words "fake" and "peace" scrawled across her bare chest was eventually apprehended by security officials.

The US President also faced criticism after the White House canceled a planned trip to the Aisne-Marne American Cemetery, 50 miles outside Paris, on Saturday due to "scheduling and logistical difficulties caused by the weather."

World leaders joined French President Emmanuel Macron at the Tomb of the Unknown Soldier, which lies at the foot of the Arc de Triomphe monument in Paris.

Also in attendance at the memorial in Paris was German Chancellor Angela Merkel, Canadian Prime Minister Justin Trudeau, Russian President Vladimir Putin and Turkish President Recep Tayyip Erdoğan.

Following Sunday's ceremony at the Arc de Triomphe, Trump attended a lunch for all the world leaders. He later visited another American cemetery, this one closer to Paris, to lay a wreath and deliver his own speech.

Speaking at Suresnes American Cemetery, Trump called out to six US veterans from World War II who were in the crowd, and a 13-year-old American boy who had saved up to attend the event.

He also paid his respects to the thousands of American soldiers who died in WWI: "It is our duty to preserve the civilization they defended and secure the peace they so nobly gave their lives for one century ago."

Trump is due back in Washington by Sunday evening.

Camilla, Duchess of Cornwall, Queen Elizabeth II and Catherine, Duchess of Cambridge, attend the Remembrance Sunday ceremony at the Cenotaph in central London.

Meanwhile, across the English Channel, royals and senior politicians gathered with veterans and members of the public at the Cenotaph in central London for Sunday's remembrance service.

At 11 a.m. the United Kingdom fell silent for two minutes to mark 100 years since the end of WWI, and to remember the approximately 900,000 Britons who gave their lives.

Meghan, Duchess of Sussex attended the Remembrance Sunday ceremony at the Cenotaph on Whitehall in central London.

Prince Charles laid a wreath at the memorial on behalf of Queen Elizabeth II -- who watched on from the balcony of the Foreign and Commonwealth Office.

Catherine, the Duchess of Cambridge, Camilla, the Duchess of Cornwall and Meghan, the Duchess of Sussex joined the Queen on the balcony.

Prince Charles lays the Sovereign's wreath at the Cenotaph.

Earlier, Australia and New Zealand were the first to mark Armistice, where crowds gathered to pay tribute to the 60,000 Australians and 18,000 New Zealanders who died while serving for the British empire.

The view to Parliament House along ANZAC Parade during the Remembrance Day Service at the Australian War Memorial.

In Russia, while President Putin joined world leaders in Paris, commemoration services were being held across the country.

The Russian Empire, which had a population of around 150 million people, suffered 1.7 million deaths during the war.

Russian honour guards carry wreaths marking the centenary of the Armistice Day at the Brotherly cemetery of WWI heroes in Tsarskoye Selo outside Saint Petersburg.

Meanwhile, in Germany, when it comes to remembering World War I, there are far fewer memorials -- with the day being marked with muted self-reflection. There will be a commemorative concert to mark the end of the war this evening, however there is no scheduled nationwide event.

Later on in Washington in the US, the main Veterans Day memorial will take place at Arlington National Cemetery. There will be a wreath-laying ceremony at 11 a.m. local time at the Tomb of the Unknown Soldier, which will then be followed by an observance program in the cemetery's amphitheater.