South and North Korea's relations will likely face severe strains as Seoul is poised to take unilateral actions against the North following the U.N. sanctions over the country's nuclear and missile programs, experts said Thursday.

The U.N. Security Council adopted a fresh resolution on Wednesday for what has been called "the strongest set of sanctions in more than two decades" over the North's latest nuclear test and long-range rocket launch.

It will require U.N. member states to conduct mandatory inspections of all cargo going into and out of North Korea and ban the exports of mineral resources, a main source of hard currency for the cash-strapped North.

The resolution will ban aviation fuel supplies to North Korea and its exports of coal, iron and other mineral resources which account for about half of the North's total outbound shipments.

Experts said that the tougher sanctions are likely to hamper inter-Korean ties, raising a possibility that the North may conduct provocative acts in retaliation.

"The ban on exports would curtail the North's dollar earnings, inevitably crimping supplies to the military," said Jeung Young-tae, a senior researcher at the Korea Institute for National Unification. "If the effects of the sanctions are long-drawn, the North could seek to raise military tension through provocations."

Ken Gause, a senior analyst on North Korea at CNA Corp. in the United States, said that for the foreseeable future, inter-Korean relations will remain frayed as North Korea has entered into a period of brinksmanship.

Seoul-Pyongyang relations underwent a short-lived conciliatory mood last year following their rare deal in August on easing military tension.

But the North's latest provocations have completely changed the shape of regional security.

"North Korea can carry out provocative acts by firing short-to mid-range missiles when Seoul and Washington kick off their joint military drills in March," said Cheong Seong-chang, a senior researcher at the Sejong Institute. "Additional nuclear tests cannot be excluded."

South Korea is considering slapping its own unilateral sanctions on Pyongyang in a bid to help the U.N. resolution be fully implemented.

Last month, it shut down a joint industrial park in the North's border city of Kaesong to prevent money that flowed into the factory zone from bankrolling the North's weapons development effort.

Measures under review are believed to include an entry ban on vessels that have traveled through North Korea and having a tighter grip on Seoul's existing punitive sanctions imposed in May 2010.

South Korea has imposed sanctions prohibiting inter-Korean economic and other exchanges to punish Pyongyang for the sinking of a South Korean warship in March of that year.

The government has also suspended civilian inter-Korean exchanges or approval of South Koreans' visits to North Korea since Pyongyang's fourth nuke test in January.

"By strictly carrying out the existing sanctions, the government plans to come up with punitive measures so that we can fully implement the U.N. resolution," said an official at the Ministry of Unification.

Analysts said that the sanctions, if faithfully enforced, are also likely to dent the North's move to prepare for its ruling party's congress slated for May.

As the Workers' Party of Korea is preparing to hold its first congress in more than three decades in May, the North is pushing its people into working hard in its "70-day campaign of loyalty."

North Korean leader Kim Jong-un has been pursuing his signature policy of carrying out nuclear and economic development in tandem, commonly known as the "byeongjin" policy. Seoul and Washington have warned that the North's dual-track policy is a dead end.

Since Kim inherited power in late 2011, the North's economy has posted marginal growth.

North Korea's economy is estimated to have grown 1 percent in 2014, similar to a 1.1 percent on-year gain the previous year, according to South Korea's central bank. It posted economic growth for the fourth straight year in 2014 after contracting in 2009 and 2010.

Analysts said that the new sanctions would compromise the North Korean leader's move to establish economic feats ahead of the party's congress.

Cheong at the Sejong Institute said that the sanctions will likely prompt the North to scale back its party event and squeeze more North Koreans into being mobilized for it.

"North Korea will try to gather funds by pressing the 'donju' and other segments of the elite for even more loyalty payments, which will cause tensions inside the regime," Gause said, referring to the newly-emerged affluent class in the North. (Yonhap)