"America's commitment to peace in the region, and to the security of our friends, is unbreakable," Cheney said during a commemoration ceremony at the Korean War Veterans Memorial.
The anniversary comes as tensions between North Korea and the United States have intensified. North Korea test-fired seven missiles this month, prompting a U.N. Security Council resolution condemning the tests and banning any missile-related dealings with the country.
Meanwhile, Pyongyang has refused since November to participate in formal talks with the United States and four other nations aimed at halting its nuclear weapons development. North Korea says Washington first must lift financial restrictions imposed for alleged illegal activities including counterfeiting; the U.S. says that issue is unrelated to the talks.
Cheney recalled that the United States lost more than 36,000 troops in just three years of fighting, from 1950 to 1953, and that South Korea suffered horrible losses among both its military and civilians. He said the suffering continues in North Korea today.
"North Korea is a scene of merciless repression, chronic scarcity and mass starvation, with political prisoners kept in camps the size of major cities," said Cheney, who was the keynote speaker at the ceremony that drew a few hundred veterans and other observers despite a heat index of nearly 100 degrees. About half the chairs at the hourlong ceremony, held under open skies with no shade, sat empty.
Because the war ended in a cease-fire, not a peace treaty, the two Koreas are still technically at war. South Korea's 650,000 troops face the communist North's 1.1-million-strong military, the world's fifth largest, across a heavily armed border. About 29,500 American troops are also stationed in South Korea as a deterrent against North Korea.
"All of us look to the day when the light of freedom and progress covers all of Korea, and stability on the peninsula rests on a foundation of peaceful reconciliation," Cheney said. "Until then, stability and peace will be maintained by our great military alliance. Tens of thousands of American troops proudly serve in Korea today. We will maintain our presence there."