U.S. Defense Secretary Robert Gates and Russian counterpart Anatoliy Serdyukov met Wednesday to renew military-to-military relations between their countries that have been mostly closed for the past two years.

Gates met with Serdyukov for five hours of talks, followed by a private riverboat dinner marking Serdyukov's first visit to the United States and the first time a Russian defense minister has visited the Pentagon since 2005, according to Pentagon Press Secretary Geoff Morrell.

The defense chiefs signed a memo outlining the U.S.-Russia military relationship that places defense cooperation as a cornerstone of broader relations, and notes shared threats and similar challenges.

They also signed an agreement creating a defense relations working group that is to resolve issues in armed forces reform and transformation, defense policy priorities and national security, transparency and confidence-building, and regional and global security.

Gates said at the signing that he and Serdyukov will meet at least once a year and that the two nations will have more frequent exchanges among military officials.

"Today we begin what I believe will develop into more frequent communication between each other and our staffs, and I look forward to our continued work together," Gates said. "I wish him all success, and I'm hopeful we can learn from each other."

Serdyukov said the two "had very profound and detailed discussions," with each offering various proposals.

The two discussed a range of issues including defense reforms, the Strategic Arms Reduction Treaty, regional and global security, operations in Afghanistan, as well as the northern supply route through Russia and other countries the United States and NATO use as a main supply route into the combat theater, according to the Pentagon.