A day after North Korea defied international warnings by firing a cascade of missiles, South Korea's policy of quietly engaging Pyongyang is coming under scrutiny. As political leaders call for North Korea to be held accountable for its actions, officials in Seoul say they are reviewing policies ranging from food aid to economic cooperation.

South Korean President Roh Moo-hyun says North Korea's missile launches, and its defiant promise that more launches will come, should be addressed diplomatically. A statement from his office says the problem should be handled through dialogue that "does not further increase tension on the Korean peninsula."

Regional security experts say that Pyongyang's missile launches Wednesday have put President Roh in a difficult position. He has staked much of his administration on a policy of engagement with and assistance to the North - mostly free of conditions or criticism.

On Thursday, South Korean Unification Minister Lee Jeong-seok told lawmakers that even though the concept of engagement remains in place, South Korea may now have to adjust its dealings with Pyongyang.

Lee says the government is considering measures that would make North Korea realize the practical burden it has created through its actions.

Earlier, the Foreign Ministry said the government would review aspects of North-South cooperation, including Seoul's massive food aid to the impoverished North.

Mr. Roh's engagement policy has put him at odds with South Korea's long-time ally, the United States. The Bush administration prefers a tougher stance toward North Korea and is calling for United Nations Security Council action against Pyongyang in response to the missile launches.

The launches are the latest setback for the engagement policy. In May, North Korea canceled a test of North-South rail links just hours before it was due to take place. Former President Kim Dae-jung hoped to create good will by visiting the North on last month's anniversary of his historic 2000 summit with North Korean leader Kim Jong-il - but that trip was canceled because of launch preparations.

And many citizens are calling on the South Korean government to take a tougher stand toward Pyongyang on human rights and the issue of hundreds of South Koreans the North is suspected of having kidnapped.

South Korea's largest two political parties expressed anger over the launches. Kim Geun-tae, chief of President Roh's Uri party, says North Korea directly defied the South's warning.

He says the government must investigate Pyongyang's intentions and make a clear report to the people.

In parliament Thursday, Uri party lawmakers were critical of what they described as the government's slow reaction to the North Korean missile launches. They also faulted the administration for underestimating the possibility of a launch.

Kim Yeon-soon, leader of the opposition Grand National Party, or GNP, is even stronger in her rebuke.

The GNP leader says North Korea's dual pursuit of nuclear weapons and advanced missile technology is, "absolutely evil."

Opposition leaders have long argued that Seoul should make food aid and economic ventures contingent on positive developments in North Korean policies, ranging from security to human rights. GNP leaders said Thursday the launches prove Seoul should take a firmer stance, and possibly even consider economic sanctions.

Kim Tae-hyo, a political scientist at Sunkyunkwan University in Seoul, says the Roh administration's key beliefs about the North may be flawed.

He says the administration is struggling to uphold its policy that North Korean military matters should be dealt with separately from economic cooperation. He adds that Seoul is facing pressure to insist North Korea behave in line with international standards.

The crisis is made more urgent by North Korea's refusal to return to talks on implementing its pledge to end its nuclear weapons programs. Political experts in Seoul say President Roh may find himself under increasing pressure to use more than just words to influence Pyongyang's behavior.