North Korea on Tuesday repeated its denial of responsibility for the 2010 torpedo attack on the South Korean corvette Cheonan, raising pressure on Seoul to lift a package of economic sanctions against it that was imposed after the tragedy.

The denial came as Seoul has called on Pyongyang to take “responsible steps” including an official apology for the attack that killed 46 sailors, if it wants the so-called May 24 sanctions to be lifted. The sanctions ban all cross-border economic exchanges except for the operation of the inter-Korean industrial park in Gaeseong.

“Seoul has called for an apology or an expression of regrets over the sinking before the sanctions are lifted. Such sophistry is not going to work for good,” the North’s powerful National Defense Commission said in a statement issued two days before the fifth anniversary of the attack.

“Our consistent claim is that the sanctions that were conjured up based on fabrications (about the sinking of the Cheonan) should be lifted without delay.”

The NDC also renewed its calls for a joint probe into the sinking, arguing that it can confidently establish its innocence.

“Should the South bring all pieces of evidence regarding the sinking of the Cheonan to the inter-Korean border village of Panmunjeom or any place, we can immediately explain to the world what the truths really are,” said the statement.

A Seoul-led multinational investigation team concluded in May 2010 that the 1,200-ton vessel was torpedoed by a North Korean midget submarine in the West Sea. The team presented the conclusive evidence ― the North Korea-made torpedo part retrieved from the scene.

As for the May 24 sanctions, the Seoul government has recently shown a flexible stance, saying it can discuss all pending issues including the sanctions, the resumption of tours to Mount Geumgangsan and reunions of separated families, when the two Koreas resume talks.

But the North has called for the lifting of the sanctions as a precondition to start the long-stalled bilateral dialogue. Cross-border tension has also been ratcheted up as the North hardened its rhetoric against the ongoing South Korea-U.S. military drills.

Amid the deadlock in the inter-Korean ties, calls have been growing for Seoul to consider lifting the sanctions. Over the issue, cracks have emerged in the ruling Saenuri Party with some still maintaining a tough stance against the North and others calling for more reconciliatory gestures.

Meanwhile, Saenuri Party floor leader Rep. Yoo Seong-min pressed the main opposition New Politics Alliance for Democracy to recognize the North’s culpability for the sinking of the corvette, noting that the liberal party has so far shown a “vague” stance on the issue.

“The NPAD can start as a party focusing on security when it clearly recognizes the North’s responsibility for the attack,” he said during a meeting with party lawmakers.

The NPAD has recently vowed to become a party focusing more on security issues as the rival parties are gearing up for the April 29 by-elections in which four parliamentary seats are up for grabs.

By Song Sang-ho (sshluck@heraldcorp.com)