The conference is the second since 2012, when Canada hosted the first North American defense ministers meeting, and on the flight here, Hagel told reporters traveling with him that it's important to keep the momentum going.
"Every time we meet," he said, "we add muscle and sinew --substance -- to what we're doing and what we could be doing."
Hagel said the defense ministerial arose from President Barack Obama's attendance in February in Toluca, Mexico, with Mexican President Pena Nieto and Canadian Prime Minister Stephen Harper at the North American Leaders Summit.
There, the leaders discussed their vision for a prosperous and secure future for North American citizens and a shared commitment to work together to realize that vision.
The leaders announced initiatives by the three countries to enhance competitiveness in the global economy, expand opportunities for North American citizens, and promote peace, security and development through multilateral action.
The secretary said his visit here would focus on the importance of the region and specific relationships within the region -- in particular, the trilateral relationship among the United States, Mexico and Canada.
"I don't think over the years we've done enough to reach out to our Latin American partners, partly because we suffer from a pretty good relationship," Hagel said. "The places that get most of the attention around the world are the trouble spots."
A senior defense official traveling with the secretary said the focus on the North American trilateral relationship "is the defense component of what we're trying to do in the [Western] Hemisphere -- drawing the United States, Mexico and Canada closer together as three partners."
"We've always had very strong bilateral relationships with both countries, and it's not meant to supplant those ... relationships, but we're trying to leverage the capabilities of all three countries," the official added.
And because the three nations share threat perceptions and interests in so many places in the region and increasingly around the world, the defense official said, the focus on the trilateral partnership is an effort to build on those shared interests.
The official said the defense ministers would meet in several different kinds of meetings, large and small. Though the trilateral conference involves three countries, four ministers will attend the meetings, because in Mexico, two government ministries are directly responsible for national defense: the Mexican National Defense Secretariat, shortened as SEDENA in its Spanish acronym, and the Navy Secretariat, SEMAR.
Hagel's counterparts in Mexico are Secretary of National Defense Gen. Salvador Zepeda Cienfuegos and Naval Secretary Adm. Vidal Francisco Soberon Sanz, and the secretary will meet with them for the first time today.
These military officers hold Cabinet rank and have regular and direct access to the Mexican president, who also is supreme commander of the armed forces.
Hagel has met with his Canadian counterpart several times, the defense official said, most recently in February during a NATO defense ministers meeting in Brussels.
When the two leaders met here today, Pentagon Press Secretary Navy Rear Adm. John Kirby said, they discussed a range of issues of mutual concern, including the situation in Ukraine, recent developments in the Asia-Pacific region, and common security challenges in the Western Hemisphere.
During the 30-minute meeting, Kirby added, both Hagel and Nicholson "expressed eagerness to discuss in more detail ways in which all three nations can work more closely together to deal with the threats posed by criminal networks, cyberattacks and natural disasters."
Hagel also thanked Nicholson for his leadership and for Canada's strong contributions to the NATO alliance, the press secretary said, including the International Security Assistance Force mission in Afghanistan.
The senior defense official characterized Hagel's visit here as a great opportunity to establish relationships with partners in the Western Hemisphere and to continue to work with Mexico on the bilateral relationship with the United States.
"The Mexicans are our regional partners, regional leaders, and increasingly, in the world they're becoming more of a global player," the defense official said.
"The relatively new president of Mexico made quite a splash on the world scene, and he's got big challenges at home with the economy," he added, "but he's an impressive leader, and President Obama had a good meeting with him a couple of months ago."
As indicated by the potential sale of 18 Black Hawk helicopters by the United States to Mexico, as announced this week by the State Department, the Mexicans are interested in acquiring a range of U.S. capabilities, the official said.
The potential Black Hawk sale is a high-visibility request by Mexico, he added, "but we are talking to them about a range of capabilities that they are interested in, ... like our assistance in their own security."
"There are partnership things we can do and things we can do together," he added, "but they also want to acquire their own capabilities, and we're interested in helping."
When Hagel leaves Mexico, he'll travel to Guatemala to meet with defense and government leaders
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