'We're all shaken by it,' says Obama on Canada shooting

United States President Barack Obama has condemned deadly shootings in Canada and offered assistance in the wake of the attacks in Ottawa that left 1 soldier dead.

"We are all shaken by it, but we're going to do everything we can to make sure that we're standing side by side with Canada during this difficult time," Obama told reporters during a brief media interaction at his Oval Office.

Obama spoke with Prime Minister Stephen Harper to express the American people's solidarity with Canada in the wake of attacks in Quebec on October 20 and in Ottawa on October 22.

Condemning the attacks, he reaffirmed the close friendship and alliance between the two countries and offered any assistance Canada needed in responding to these attacks.

"The situation there is tragic. Just two days ago, a Canadian soldier had been killed in an attack. We now know that another young man was killed today. I expressed on behalf of the American people our condolences to the family and to the Canadian people as a whole," Obama said.

"We don’t yet have all the information about whether this was part of a broader network or plan, or whether this was an individual or series of individuals who decided to take these actions. But it emphasises the degree to which we have to remain vigilant when it comes to dealing with these kinds of acts of senseless violence or terrorism," Obama said.

The US national security team, he said, was coordinating very closely with Canada.

"It is very important I think for us to recognize that when it comes to dealing with terrorist activity, that Canada and the United States has to be entirely in sync," he said.

In a statement, Secretary of State John Kerry condemned the "heinous and evil attacks" in Ottawa and said it was aimed at the heart of the federal government itself.

"The United States has faced this kind of violence firsthand on our own soil, and we grieve with Canada, seared by the memory of our own painful experiences," he said.

In a telephonic conversation with his Canadian counterpart, Kerry pledge "full support" to Canada as it works to determine the facts and to hold those accountable responsible.

"The US strongly condemns today's shootings in Ottawa, as well as the hit-and-run attack in Quebec earlier this week. The United States has no closer friend and ally than Canada, and the United States military has no closer partner than the Canadian Armed Forces," Defence Secretary Chuck Hagel said.

The Department of Defence, including through the North American Aerospace Defence Command, will continue to monitor the situation closely and stands ready to assist our Canadian allies in the aftermath of these tragic events, Hagel said.

Congressman Ed Royce, Chairman of the House Foreign Affairs Committee, said he is deeply troubled by the attack that took place in Ottawa.

"This was an attack against the heart of Canada’s government, an attack against Canadian democracy," he said.