UNITED NATIONS -- North Korea's leadership has cracked down further on human rights as tensions have escalated over its nuclear missile tests, including beefing up restrictions on movements and making "horrific" prison conditions more severe, the U.N. rights chief said Monday. Zeid Ra'ad al-Hussein told the Security Council that the international security crisis sparked by North Korean leader Kim Jong Un's military actions "is inseparable from concerns about the human rights situation of the ordinary people in the country."

A chronic lack of food, partly due to resources which are diverted to the military, has made humanitarian aid provided by the U.N. and others "literally a lifeline for some 13 million acutely vulnerable individuals," he said.

Zeid urged the Security Council to assess the human rights impact of sanctions — including controls over international banking transfers — that have slowed aid deliveries and to minimize the humanitarian consequences.

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This was the fourth year the Security Council has discussed human rights in the Democratic People's Republic of Korea, or DPRK, the country's official name. As in previous years, the meeting only went ahead after a procedural vote in the 15-member council where at least nine nations are required to support having the session.

On Monday, the human rights meeting was approved by 10 council members and opposed by Russia and China, with Egypt and Ethiopia abstaining. China's deputy U.N. Ambassador Wu Haitao, whose country is the DPRK's closest ally, said the meeting would be "counterproductive" at a time of heightened tensions.

North Korea's response was, unsurprisingly, angry and swift, reports CBS News' Pamela Falk. A statement that was sent to CBS News from Kim Jong Un's U.N. mission reads in part: "We strongly condemn the meeting as a desperate act of the hostile forces which lost the political and military confrontation with the DPRK that has openly risen to the position of nuclear weapon state," adding that the Council's "despicable plot cannot frighten the DPRK."

The human rights meeting and furious North Korean response come two days after U.N. Undersecretary-General for Political Affairs Jeffrey Feltman returned to New York from Pyongyang after meeting with high-level representatives of the government, hoping to restart a dialogue. Feltman said he told the North Koreans of "the urgent need to prevent miscalculations and open channels to reduce the risks of conflict."

North Korea's latest ballistic missile test demonstrated that it can threaten the U.S. mainland, and there is growing concern that the DPRK will soon be able to put a nuclear warhead on its missiles. President Donald Trump has vowed to stop the North Koreans from reaching such capability, increasing the possibility of conflict.

"Indeed, the context of military tensions seems to have deepened the extremely serious human rights violations endured by the DPRK's 25 million people," the U.N. high commissioner for human rights said.

North Korea has barred U.N. human rights officials from visiting the country, and its government has vehemently opposed the Security Council meetings on its rights situation and the annual resolutions by the U.N. General Assembly condemning its rights record. The DPRK maintains that it upholds human rights.

But Zeid said people who have escaped from North Korea have reported "extremely widespread violations of rights in almost every aspect of people's lives."

"In recent months, military tensions have led to more severe controls over freedom of movement and civil and political rights for the people of the DPRK," he said.

Zeid pointed to new physical barriers being erected along North Korea's border and increased surveillance.

He also criticized China for returning North Koreans who escape from their country, saying they "are routinely subjected to multiple forms of torture and ill-treatment," including women who are subjected "to invasive body searches" that may amount to rape under international law.

Zeid said his office has received more than 70 reports of women, men and children who escaped from being sent back after Chinese authorities decided they were "economic migrants," disregarding "the overwhelming human rights violations taking place in the country."

He also cited horrific conditions in prisons and labor camps, and widespread torture in detention centers used to extract information or confessions about people planning to leave the country, illegally using foreign telecommunications networks to contact people abroad, or engaging in smuggling activities.

Detainees are forced to work in mines or on building projects, face beatings, "and are being fed so little they barely survive," Zeid said.

There are reportedly five secret political prison camps which instill fear and function as "a powerful instrument of control," he said.

U.S. Ambassador Nikki Haley told the council that the systematic human rights violations against North Korea's people "are a means to a single end: Keeping the Kim Jong Un regime in power."

"The regime is using that power to develop an unnecessary arsenal and support enormous conventional military forces that pose a grave risk to international peace and security," she said. "Their menacing march towards nuclear weapons begins with the oppression and exploitation of ordinary North Korean people."

Haley said an estimated 100,000 North Koreans, including children, are in prisons, many because the DPRK practices "guilt-by-association" and allows up to three generations of a family to be imprisoned along with the accused family member.

"Defectors have reported that all North Koreans age 12 and older are required to attend public executions — a graphic reminder of consequences of disobedience of the government," she added.

Haley said the majority of asylum seekers are women, many of them trafficked. If women are repatriated while pregnant, she said they are tortured and forced to have abortions. If their baby is born alive, it is killed in an effort to maintain "ethnic purity," she said.

Haley brought two women defectors to speak about their escapes and lives in DPRK camps at an informal council meeting later in the day.