The United States will not resort to establishing a new legislation to punish North Korea for the Cheonan warship incident as it sees that new legal measures won’t have its intended effect on the already isolated regime as well as due to the technical difficulty of scrapping the law later once it becomes enacted, Yonhap news agency said, Saturday.

“We will apply measured sanctions against North Korea, as we have in the past, and tailored to help influence the thinking of the government and those who support the government, " State Department spokesman Philip Crowley said, explaining the “two track strategy” of Washington in handling Iran and North Korea differently.

Crowley's remarks come amid reports that Washington does not intend to craft legislation to sanction foreign companies involved in illegal transactions with North Korea, unlike the case with Iran, it said.

Some officials and analysts in Seoul and Washington alike say the isolated North Korean economy is already feeling the pinch from a variety of sanctions and nothing much can be achieved through any further sanctions.

They also doubt the effectiveness of further sanctions on the North, let alone symbolism, without substantial cooperation from China, which has focused more on reviving the six-party nuclear talks.

The U.S. has said it will establish "new executive authorities" rather than resorting to legislation, which is difficult to reverse, to try to persuade the international community to voluntarily cut off ties with listed North Korean entities and individuals.

Washington froze more than $25 million in North Korea’s accounts in the Banco Delta Asia in Macau in 2005, designating it as an entity suspected of helping North Korea launder money it earned by circulating counterfeit $100 bills called supernotes.

Due to procedural matters, the U.S. had difficulty in lifting the freeze in early 2007 to entice the North to come back to the six-party talks on ending its nuclear weapons programs. However, the freeze effectively cut off Pyongyang's access to the international financial system and dealt the nation a devastating blow, it said.