Chanting slogans, holding placards, and waving flags, protesters said the US is a belligerent country that is undermining peace and stability in the world, calling on Washington to stop spreading war.
"NATO's actions in Ukraine have been to expand the weapon arsenals of Ukraine, send more and more guns, bombs, missiles to Ukraine. And what this results in is just more and more deaths," Luca, a protester, told Reuters.
“There's no world in which sending more and more weapons into a conflict zone will decrease the conflicts and stop it.”
Friday marked the 24th anniversary of the beginning of the 78-day bombing of Yugoslavia by NATO, while Monday marked the 20th anniversary of the US invasion of Iraq.
"In more than 200 years of its existence, they have always been at war. So, the United States is warmongering. When the head of US imperialism comes to Canada, we want to show that he is absolutely not welcome, and he should not be coming here," said Larry Worthlon, another protester.
"I think our foreign policy should be independent from the US, and the Canadian people, we want peace," said Emily, the third protester.
Biden landed in Ottawa on Thursday for his first visit to Canada as president of the US and the first since Barack Obama visited the country in June 2016.
Previously, Biden had visited Ottawa in 2016, toward the end of his time as vice president.
Since February 2022, Canada has made more than $1 billion in military assistance to Ukraine and pledged to give more.
The most notable supplies included National Advanced Surface-to-Air Missile System (NASAMS), armored combat and support vehicles, anti-tank weapons, M777 Howitzers, small arms, and high-resolution drone cameras.
Earlier this month, Canadian Defense Minister Anita Anand confirmed a new tranche of munitions for Ukraine during a virtual meeting led by US counterpart Lloyd Austin.