North Korea's push for a long-range rocket launch is seen as aimed at achieving feats on the military front for internal solidarity ahead of its key party event in May, experts said Wednesday.

The North also appears to be trying to counter the U.S.-led campaign to slap stronger sanctions on the North over its fourth nuclear test last month, they added.

North Korea notified the International Maritime Organization on Tuesday that it will launch what it calls an "earth observation satellite" between Feb. 8 and Feb. 25.

The United Nations Security Council has been working on fresh sanctions against North Korea over its nuclear test on Jan. 6.

Experts said the North is likely to blast a rocket around Feb. 16, the birthday of former North Korean leader Kim Jong-il, who died due to heart failure in late 2011.

"North Korea is likely to launch a rocket around the former leader's birthday as a kind of gun salute," said Kim Yong-hyun, a professor of North Korean studies at Dongguk University.

A pro-North Korean website in the United States said earlier that whether or when the North will launch a long-range rocket will be entirely the decision of the North's leader Kim Jong-un.

Analysts said that Pyongyang's planned rocket launch is apparently intended to add to the young leader's list of accomplishments ahead of the country's key party congress to be held in May.

"North Korea seems to seek to establish a military powerhouse by launching an intercontinental ballistic missile before the party event is held," said Cho Sung-ryul, a senior researcher at the Institute for National Security Strategy.

The Workers' Party of North Korea plans to hold its first congress in about three decades in May when the North's leader Kim will likely unveil new lines of policies and conduct a reshuffle.

By pushing ahead with the nuclear test, the North's young leader has proven that he has no intention to ditch his signature policy of seeking nuclear development and economic growth in tandem, commonly known as the "byeongjin" policy.

North Korea has claimed it has a sovereign right to launch "a series of satellites for peaceful purposes." But Seoul and Washington view the North's move as a cover for ballistic missile tests.

In December 2012, North Korea successfully put what it claims was a satellite, named "Unha-3," into orbit. About two months later, the North conducted its third nuclear test, inviting international condemnation and tough sanctions from the U.N. Security Council.

"At a time when the U.N. Security Council is discussing sanctions, the North is seen as sending a message that it will not even bat an eyelash over any punishment," said Kim, the professor at Dongguk University.

The North's notification of its rocket launch plan also came on the same day when China's top nuclear envoy Wu Dawei arrived in Pyongyang in an apparent bid to curb the North's nuke ambitions.

China is currently under international pressure to exert its leverage on North Korea to ensure that Pyongyang gives up its nuclear weapons program.

U.S. Secretary of State John Kerry and his Chinese counterpart Wang Yi agreed last week to accelerate efforts for a new U.N. resolution targeting North Korea. But the two sides have failed to narrow the gap over how severely sanctions should be.

China, North Korea's treaty ally and economic benefactor, is firmly opposed to the North's nuclear aspirations, but it is believed to be reluctant to push the North too hard out of concerns that tougher sanctions may destabilize North Korea, sparking border insecurity.

Some analysts said that the North may not go ahead with the launch, leaving the card for talks.

"If China offers aid plans, North Korea may withhold its rocket launch," said Yang Moo-jin, a professor at the University of North Korean Studies. "Whether North Korea will press ahead with the rocket launch seems to hinge on how China will use its leverage."

Inter-Korean relations will inevitably face setbacks for a while as Seoul warned Wednesday Pyongyang will "pay a harsh price" if it goes ahead with its plan to launch a rocket.

The North's missile provocation is likely to further spark a row over the possibility that the U.S. would deploy an advanced Terminal High Altitude Area Defense system on South Korean soil to deter the North's nuclear and missile threats, experts said.

China and Russia have strongly opposed the possible move by Washington, saying that it will spark an arms race in the region and hurt their security interests. (Yonhap)