The United States imposed sanctions on the sister of North Korean leader Kim Jong-un on Wednesday for her links to human rights violations in the communist nation.

Kim Yo-jong, the leader's younger sister and vice director of the Workers Party's Propaganda and Agitation Department, was among seven North Korean officials and two agencies that the State Department blacklisted for their roles in the regime's human rights violations.

It was the second time the US has imposed human rights sanctions on the North after blacklisting leader Kim Jong-un, 10 other top officials and five state agencies in July, which marked the first-ever sanctions ever imposed on the North's leader.

The sanctions underscore Washington's determination to keep pressure on Pyongyang, which has aggressively been pursuing nuclear weapons and its delivery systems at the expense of the well-being of the country's 24 million hunger-stricken population.

The six other newly blacklisted North Korean officials are Minister of State Security Kim Won-hong; senior Workers' Party officials Choe Hwi, Min Byong-chol and Jo Yong-won; provincial security official Kim Il-nam; and military official Kang Pil-hun.

The two agencies are the State Planning Commission and the Ministry of Labor.

The officials and entities were added to the Treasury Department's List of Specially Designated Nationals and Blocked Persons that calls for freezing assets of and banning American transactions with those blacklisted, though the measures are expected to be largely symbolic as North Korean officials have no assets in the US and do not engage in transactions with Americans.

North Korea has long been labeled as one of the worst human rights violators. The communist regime does not tolerate dissent, holds hundreds of thousands of people in political prison camps and keeps tight control over outside information.

But Pyongyang has bristled at such criticism, calling it a US-led attempt to topple its regime.

In April, the State Department said in its annual human rights report that the North continues to control political activity and ban or limit political opposition, while maintaining a network of political prison camps.

Pyongyang is expected to react angrily to the latest sanctions. (Yonhap)