North Korea's deadly shelling on Tuesday of a South Korean border island is paradoxically aimed at forcing the United States to hold talks about a peace treaty for the divided peninsula, analysts said.
The North fired dozens of shells onto or around the frontline Yeonpyeong island near the disputed Yellow Sea border, setting homes ablaze.
Two marines were killed and many more injured in one of the most serious border incidents since the 1950-53 Korean war.
The shelling came days after the disclosure that the North has completed work on a new uranium enrichment plant.
The communist state characteristically alternates between conciliatory and aggressive behaviour.
Pyongyang rejects the charge of sinking a South Korean warship in March but has made a series of overtures to Seoul in recent months without softening its stance.
"This (shelling) is an intentional provocation to heighten cross-border tensions," Kim Yong-Hyun, a professor, said.
"It is sending a strong message to the United States and the international community that the peninsula urgently needs a peace regime."
Pyongyang, which says it needs a nuclear shield against the threat of US aggression, has long called for talks with Washington on signing a peace pact.
Analysts say the North's regime has lived for decades in genuine fear of a US attack, especially since the Iraq invasion. It sees a peace treaty as some sort of safeguard.
The US says this can be discussed but only after the North returns to stalled nuclear disarmament talks.
And Yang Moo-Jin, of University of North Korean Studies, also said Pyongyang is sending a message to Seoul and Washington that dialogue is needed.
"North Korea is now angry at South Korea's attitude. It is intentionally raising tensions with cross-border shelling…," Yang said.
"It is telling Washington that dialogue is needed to conclude a peace pact as soon as possible." Understanding the Korean crisis