CBCNews.ca will carry the announcement live starting at 3:30 p.m. ET.
Mobile users can watch the event here.
Prime Minister Stephen Harper on Wednesday joined G7 leaders in calling on Russia to halt a referendum in Ukraine's Crimea region.
"All of the G7 countries remain collectively strongly committed to the view that we will not accept Russia's illegal occupation of Crimea," Harper said in B.C., where he stopped on his way back from South Korea on Wednesday.
The G7 group, which includes Canada, France, Germany, Italy, Japan, the United Kingdom and the United States, said in a formal statement that a Russian-backed referendum would hold no legal weight.
"We call on the Russian Federation to immediately halt actions supporting a referendum on the territory of Crimea regarding its status, in direct violation of the constitution of Ukraine," the statement said.
"Any such referendum would have no legal effect. Given the lack of adequate preparation and the intimidating presence of Russian troops, it would also be a deeply flawed process which would have no moral force. For all these reasons, we would not recognize the outcome."
More to comeSuggest a correction