Panmunjom, Korea ? Standing at the spot that divides North and South Korea, U.S. Secretary of State Hillary Rodham Clinton urged North Korea today to turn away from the isolation that has left its people suffering.

Clinton and Defense Secretary Robert Gates paid a rare visit on a rainy day to the heavily fortified border dividing the two Koreas — a symbolic trip four months after the deadly sinking of a South Korean warship blamed on the North.

Forty-six South Korean sailors were killed when the Cheonan exploded in the waters near the Koreas’ western maritime border. An international team of investigators pinned the blast on a torpedo fired from a North Korean submarine — the worst military attack on South Korea since the 1950-’53 Korean War.

Sixty years after the fighting began, the peninsula remains divided in a state of war because the conflict ended in a truce, not a peace treaty. Hundreds of thousands of troops stand ready on both sides of the 3-mile-deep DMZ, making it one of the most heavily guarded borders in the world.

“Although it may be a thin line, these two places are worlds apart,” Clinton said as North Korean soldiers stood just several feet away and civilians on the North Korean side of the DMZ watched the delegation through binoculars.

She praised longtime ally South Korea for making “extraordinary progress” in the years since the Korean War, economically and politically. “By contrast, the North has not only stagnated in isolation, but the people of the North have suffered for so many years.”

Clinton thanked the troops — U.S., South Korean and from other U.N. nations — that guard the buffer zone that stretches from east to west and lies just 30 miles from the South Korean capital.

“We continue to send a message to the North: There is another way. There is a way that can benefit the people of the North,” she said. “But until they change direction, the United States stands firmly on behalf of the people and government of the Republic of Korea, where we provide a stalwart defense along with our allies and partners.”

South Korea, also known as the Republic of Korea, has risen from the ashes of the war to become the world’s 15th-largest economy. North Korea’s economy, in contrast, has faltered for decades, with millions depending on food handouts.

“It is stunning how little has changed up there (at the observation point) and yet how much South Korea continues to grow and prosper,” Gates said. “The North, by contrast, stagnates in isolation and deprivation. And, as we saw with the sinking of the Cheonan, it continues its history of unpredictable and, at times, provocative behavior.”