SEOUL, South Korea (AP) -- North Korean leader Kim Jong Il greeted South Korean President Roh Moo-hyun in Pyongyang before thousands of cheering residents Tuesday to begin only the second summit between the two countries since the peninsula's division after World War II.

North Koreans waving pink paper flowers and a military honor guard bearing rifles with bayonets heralded the leaders' first encounter outside a cultural hall in the North Korean capital, after Roh traveled some 3½ hours by road from his capital, Seoul.

The two leaders walked down a red carpet where Kim, wearing his typical khaki military jumpsuit, introduced Roh to top North Korean leaders. Kim shook hands with members of the South Korean delegation.

Kim appeared reserved and unemotional, walking slowly and occasionally clapping lightly to encourage the crowd. Roh appeared to revel in the moment, waving and smiling broadly.

Neither made any public comment before Roh got back into his armored limousine to travel to the state guesthouse where he is staying for the summit that runs through Thursday.

Earlier during the 125-mile journey from Seoul to Pyongyang by road, Roh stepped out of his vehicle to walk across the border that divides the Koreas in the center of the heavily fortified Demilitarized Zone — the first time a South Korean leader has crossed the land border. In the first summit between the Koreas in 2000, then-President Kim Dae-jung flew to Pyongyang.

"This line is a wall that has divided the nation for a half-century. Our people have suffered from too many hardships and development has been held up due to this wall," Roh said, crossing near the North Korean city of Kaesong.

"This line will be gradually erased and the wall will fall," he said. "I will make efforts to make my walk across the border an occasion to remove the forbidden wall and move toward peace and prosperity."

For the ride into Pyongyang itself, Roh changed vehicles to an open-topped car and was joined by the North's No. 2 leader Kim Yong Nam. Many thousands of residents lined the streets chanting "Long live!" and "Welcome!"

This week's summit comes almost exactly a year after the North tested a nuclear bomb, rattling regional stability and leading to a dramatic turnaround in the previous hard-line U.S. policy toward its longtime rival.

Since then, Pyongyang has shut down its sole operating nuclear reactor that produced material for bombs and has tentatively agreed to disable its atomic facilities by year-end in a way that they cannot be easily restarted.

Before leaving the South Korean capital, Roh said he would build on the achievements from the first North-South summit and "hasten the slow march" in reconciliation between the sides, which remain technically at war since the 1950-53 Korean War ended in a cease-fire.

"I intend to concentrate on making substantive and concrete progress that will bring about a peace settlement together with economic development," he said.

Roh acknowledged that ridding the North of nuclear weapons and establishing a peace treaty could not be realized by the two Koreas alone. But he said he would work to establish a concrete agreement on "building military trust and addressing humanitarian matters."

Pyongyang has participated in international talks including the U.S. and other regional powers on its nuclear program that were set to reconvene Tuesday. A peace agreement to end the Korean War would require participation of the U.S. and China, which also fought in that conflict.

Washington expressed skepticism the summit would lead to progress on the nuclear standoff and noted that the peace issue was also being discussed at the international arms negotiations known as the six-party talks.

"I certainly am not looking for those inter-Korean discussions to change the basic facts on the ground or the six-party talks," State Department spokesman Tom Casey said Monday.

South Korean officials have declined to give specifics on what Seoul seeks at the summit, given the unpredictable nature of talks with North Korea's Kim. They have sought to play down expectations, asserting that simply having any meeting is valuable.

"Even if we do not reach an agreement in many areas, it would still be a meaningful achievement to narrow the gap in understanding and to enhance confidence in each other," Roh said.

Accompanied by industry leaders, politicians and cultural figures, Roh will spend hours in dialogue with Kim and tour the North, even taking in a massive propaganda spectacle with thousands of synchronized performers glorifying North Korea's communist regime.

Roh leaves office in February. The conservative opposition has criticized the summit as a political ploy aimed at bolstering Roh's sagging popularity, along with that of liberals aligned with him, just two months before a presidential election to choose South Korea's next president.

The North's Kim is also angling to keep the conservatives from power in Seoul, fearful they will reverse the South's policy of engagement and massive aid to its neighbor.