South Korea's president is renewing his offer of dialogue with North Korea and proposing financial aid if Pyongyang gives up its nuclear weapons and missile programs.
But in a speech Tuesday to honor South Korea's independence struggle, President Lee Myung-bak also said that North Korea must "take responsible measures" concerning armed attacks on the South last year.
The last effort at bilateral negotiations fell apart last month when South Korea insisted that the North admit it sank a South Korean warship in March of last year, and apologize for an artillery attack on the South in November. The two attacks killed 50 people.
Tensions are rising again with the beginning this week of an annual military exercise involving thousands of U.S. and South Korean forces. The North has called it a "rehearsal for invasion," and Pyongyang threatened to turn the South into a "sea of fire."
In his nationally televised speech, Lee said it is time to "open a new kind of future" between the two Koreas, and added that his government "is ready to engage in dialogue with the North anytime with an open mind."
He also said there is no reason for South Korea "not to help our compatriots in the North when it is helping many other countries."
But he also said the North "should step forward for serious dialogue and cooperation and refrain from developing nuclear weapons and missiles."
Lee said the North "has to take responsible measures regarding their armed provocations and get on the path of genuine reconciliation and cooperation."
Tuesday's national holiday celebrates the anniversary of an uprising against Japanese colonial rule in 1919.
Lee used the occasion to call for Japan "to behave and act in a genuine manner" in line with remarks made by Japanese Prime Minister Naoto Kan last year.
In the remarks, Kan expressed "deep remorse" for Japanese behavior during the colonial period from 1910 to 1945 and offered a "heartfelt apology" for those actions.
Some information for this report was provided by AP, AFP and Reuters.