South Korea has pledged support of the United States' new sanctions on North Korea, which came this week in response to the high-profile cyber attack on Sony Pictures that has further strained already tense US-North Korea relations.

The sanctions, which President Barack Obama announced Friday, were an "appropriate" consequence of North Korea's aggression, South Korea's foreign ministry said today, according to the country's Yonhap News Agency. The declaration came just as North and South Korea prepare for potentially groundbreaking negotiations to improve inter-Korean relations.

"The US government's sanctions are seen as an appropriate countermeasure against North Korea's policy and actions such as its persistent provocation including the latest Sony Pictures hacking attack," South Korea's foreign ministry said in a statement.

The new sanctions came in response to the unprecedented hacking of Sony Pictures in December, which is believed to have been caused by North Korea in response to the studio's movie The Interview, in which journalists portrayed by Seth Rogen and James Franco plot to assassinate North Korea's leader Kim Jong-un. The new sanctions will further financially isolate North Korea's military intelligence agency and other entities, the US Treasury said in a statement.

"This step reflects the ongoing commitment of the United States to hold North Korea accountable for its destabilizing, destructive and repressive actions, particularly its efforts to undermine US cyber-security and intimidate US businesses and artists exercising their right of freedom of speech," the Treasury explained in the statement.

The treasury said that it designated three North Korean entities in the sanctions — the Reconnaissance General Bureau, North Korea's primary intelligence organization; the Korea Mining Development Trading Corporation, a primary arms dealer; and the Korea Tangun Trading Corporation, which supports North Korea's defense research and development programs. The sanctions will also affect 10 individuals, according to the treasury.

Amid waning belief among cyber security experts that North Korea is in fact responsible, US intelligence officials are maintaining the country conducted the attack — which included threats against moviegoers and the hacking of Sony's computer system. North Korea has denied any responsibility.

The new sanctions hold more political than practical weight, since North Korea is already severely financially isolated, analysts told Reuters.

"It's not as if they travel a lot abroad to western Europe or the United States," Joel Wit of the US Korea Institute at Johns Hopkins University said. "They don't have billions of dollars in western banks."

In a televised speech on New Years Day, Kim had proposed a thawing of the cold relations between North and South Korea.

"Depending on the mood and circumstances to be created, we have no reason not to hold the highest-level talks," Kim said.

On Friday, Seoul's unification ministry encouraged Pyongyang to return to negotiations to improve South-North ties.

"The North will have to engage in dialogue without attaching preconditions if it has a genuine will for the improvement of South-North ties," ministry spokesman Lim Byeong-cheol said, also confirming that South Korea will not restrict the format of the talks.