North Korea has described US sanctions against Kim Jong-un and other senior officials for human rights abuses as a “declaration of war”. Pyongyang said the announcement of sanctions was a “hideous crime”, according to North Korea’s official KCNA news agency.

The United States imposed its first sanctions targeting any North Koreans for rights abuses on Wednesday, blacklisting Kim along with 10 other people and five government ministries and departments. The move affects assets within US jurisdiction.

UN secretary-general Ban Ki-moon, a former South Korean foreign minister, hopes China will urge its ally North Korea to cooperate internationally on human rights, his spokesman Stephane Dujarric said on Thursday in New York.

Dujarric said that Ban, who is currently visiting China, “believes that discussion of human rights concerns allows for a more comprehensive assessment and action when addressing security and stability concerns on the Korean peninsula.”

China’s foreign ministry said it opposed the use of unilateral sanctions when asked about the US move. China argues that the human rights situation in North Korea is not a threat to international peace and security and has sought to prevent the issue being discussed at the UN security council.

US secretary of state John Kerry said he had spoken to China’s foreign minister Wang Yi and hoped that Beijing would continue to cooperate with the United States UN sanctions aimed at rolling back North Korea’s nuclear weapons program.

North Korea has been under UN sanctions since 2006. In March, the security council imposed harsh new sanctions on the country in response to North Korea’s fourth nuclear test in January and the launch of a long-range rocket in February. Some analysts and diplomats have warned that the US move could limit cooperation with China on further action.

Samantha Power, the US ambassador to the United Nations, said last month that the United States would seek to identify people and entities linked to a series of recent ballistic missile tests by Pyongyang, in violation of a UN ban, who could be sanctioned by the UN security council. The cooperation of China and Russia would be needed for any further designations.

Senior US administration officials said the new US sanctions showed the administration’s greater focus on human rights in North Korea, an area long secondary to Washington’s efforts to halt Pyongyang’s nuclear and missile programs.

“Under Kim Jong-un, North Korea continues to inflict intolerable cruelty and hardship on millions of its own people, including extrajudicial killings, forced labor, and torture,” said Adam J Szubin, acting undersecretary for Terrorism and Financial Intelligence, in a statement.

Inside North Korea adulation for Kim, 32, is mandatory and he is considered infallible. A 2014 report by the United Nations, which referred to Kim by name in connection to human rights, triggered a strong reaction from Pyongyang, including a string of military provocations.

The US treasury department identified Kim’s date of birth as 8 January 1984, a rare official confirmation of his birthday.

South Korea, which cut all political and commercial ties with its own sanctions against the North in February, welcomed the US move, saying it will encourage greater international pressure on the North to improve its human rights record.

