South Korea's president called Monday for cooperation with North Korea and pledged limited humanitarian support for its impoverished people as the two nations try to set aside animosity and pursue dialogue South Korea's president, Lee Myung-bak's speech celebrating the Korean peninsula's liberation from Japan's 1910-1945 colonial rule followed tentative talks among officials from the United States, North Korea and South Korea aimed at restarting international negotiations to persuade the North to abandon its nuclear weapon ambitions. Lee, wearing traditional clothes, said Koreans long for reunification despite the peninsula's bitter history. Although known as a hard-liner on North Korea, Lee has often sought to strike a balance between diplomacy and strength, offering dialogue for any signs of North Korean goodwill. Both the totalitarian North and democratic South champion the idea of reunification, but each sees its own system of government as the leading force in any single Korea. "South and North Korea have lived in an age of confrontation for the last 60 years," Lee said in the nationally televised speech. "Now we must leap beyond that age and live in an age of peace and cooperation." Korea was divided after the end of Japanese rule and technically remains in a state of war because the 1950s Korean War ended with an armistice, not a peace treaty. Despite the president's conciliatory tone and recent signs that the nuclear talks stalled since 2008 might resume, tensions between the countries remain high. U.S. and South Korean forces are to begin joint military drills this week, and South Korea says it exchanged artillery fire with the North last week along their disputed maritime border. North Korea says the South overreacted to construction noise. Last year was a bloody reminder of the animosity between the Koreas. Seoul says a North Korean torpedo sank one of its warships in March 2010, killing 46 sailors; a North Korean artillery attack in November killed two civilians and two marines on a front-line South Korean island. Lee also said in his speech that humanitarian support for North Korean children and victims of natural disasters will continue. North Korea has faced weeks of torrential rain, leading to widespread deaths and property loss. Since taking office in 2008, Lee has halted large-scale food aid to North Korea pending progress in nuclear disarmament. But his conservative government has provided occasional aid to vulnerable children, pregnant women and disaster victims. Recent weeks have seen renewed diplomatic hope. A senior North Korean official met last month with U.S. counterparts in New York to negotiate ways to restart the nuclear talks. That meeting followed friendly talks between North and South Korean nuclear envoys during a regional security forum in Indonesia. South Korean leaders often call for a peaceful reunification with the North, although many in Seoul are wary of the huge social and economic costs of absorbing the impoverished North. North Korea also has called repeatedly for reunification, but it imagines integration under its own totalitarian political system. Tensions could flare again. Allies South Korea and the United States plan to begin more than a week of drills starting Tuesday that simulate a military crisis with the North. North Korea has demanded the cancellation of the annual exercises, calling them a hindrance to diplomacy. In downtown Seoul, several thousand gathered Monday to voice anger at Japan and North Korea. South Korea disputes Japan's claim to a group of islets in waters between the countries, and many in Seoul are still angry over Tokyo's colonization of Korea. Near the heavily armed border with the North, conductor Daniel Barenboim, known for his Middle East peacemaking efforts, planned later Monday to lead an orchestra of young musicians from Israel and Arab countries in an outdoor "Peace Concert" featuring Ludwig van Beethoven's Ninth Symphony. In Pyongyang, North Korea's official media reported that people from all backgrounds laid flowers in front of a statue of late founder Kim Il Sung, who is credited in the North with liberating Korea from Japan in a long armed struggle.