Army Gen. Charles Jacoby Jr., commander of North American Aerospace Defense Command and U.S. Northern Command, joined Lt. Gen. Walter Semianiw of the Canadian army, commander of Canada Command, during defense meetings in the Canadian capital of Ottawa to sign three key documents that strengthen the combined defense and security of the United States and Canada, Northcom officials reported.

The new Combined Defense Plan establishes a planning framework to enhance defense cooperation between the two countries in the event their governments need each other’s assistance, such as during a natural disaster or attack, officials explained.

Jacoby and Semianiw also renewed for the next two years the Civil Assistance Plan that allows the military from one nation to support the armed forces of the other nation during a civil emergency. That agreement, in effect since 2008, recognizes the role of each nation’s lead federal agency for emergency preparedness, but facilitates military support of civil authorities once government authorities have agreed on an appropriate response, officials said.

In the United States, the Homeland Security Department would be the lead agency. In Canada, it would be Public Safety Canada.

A third document signed yesterday, the Information Sharing Memorandum of Understanding, updates and formalizes existing arrangements to promote information-sharing among the three organizations, officials said.

Jacoby said the documents reinforce an already-strong defense relationship.

“Canada and the United States are great security partners who have worked together for over half a century,” he said at the signing.

“These three documents provide us with the necessary means to better coordinate our combined military resources to help our fellow Americans and Canadians during emergencies,” Jacoby continued. “They help us be better prepared to defend the interests of our two great countries.”

The signing took place as both generals attended meetings of the Permanent Joint Board of Defense, the highest-level defense forum between the United States and Canada. The current meeting, the 228th in the body’s 70 years, featured talks on continental defense and security cooperation, regional engagement and the arctic.

Canadian Defense Minister Peter MacKay, who delivered the keynote address at the forum lastTuesday night, told participants the new agreements promote combined defense of the United States and Canada during peace, contingencies and war.

They describe the authorities and means by which the two governments would approve homeland military operations in the event of a mutually agreed threat, and how the two militaries would collaborate and share information, he added.

MacKay emphasized the close defense and security relations between the two countries, calling the bilateral military-to-military relationship a model for broader cross-border cooperation between civilian agencies as well.

He cited the value of the Permanent Joint Board on Defense in promoting this relationship.

“The United States is Canada’s most important ally and defense partner, and strategic discussion entrench our defense relationship at a critical time,” he said.