"Just briefly, let me congratulate American authorities for their rapid action that is obviously leading us towards a conclusion of these terrible events," he said at an event in Brantford, Ont.
"Canada, of course, always stands ready to assist our American friends. And let me repeat just one more time our condolences to all the friends and families of the victims. I do note that unfortunately there was one additional victim overnight."
In Ottawa, Public Safety Minister Vic Toews said he wouldn't answer questions on the investigation in Boston.
"I'm not going to comment on an ongoing investigation by the FBI and the American police. All I can say is that as a result of the events in Boston, [Canada Border Services Agency] is obviously in a heightened state of security."
Toews said terrorism is a worldwide phenomenon.
"It doesn't recognize national boundaries. It's something that I've been saying for many, many years, so this is not a surprising development if what is being reported is true."
Ottawa runners arrange march
Meanwhile, Ottawa runners are organizing a march on Monday from Parliament Hill to the American Embassy about one kilometre away.
People will congregate on Parliament Hill where Phil Marsh, regional manager of the local Running Room stores, and Sharon Johnston, wife of Gov. Gen. David Johnston, will speak.
Dylan Wykes, who competed for Canada at the London Olympics, will lead the walk.
U.S. Ambassador David Jacobson will speak once the walkers reach the embassy, followed by a minute of silence.