BEIJING (USA TODAY) - Several nations including the United States and China assailed North Korea on Tuesday for conducting a nuclear test, and the United Nations Security Council called the test "a clear threat to international peace and security."

The Security Council issued a statement that cited a resolution it approved unanimously last month that stepped up sanctions and promised "significant action" in the event of a new nuclear test.

"In line with this commitment and the gravity of this violation, the members of the Security Council will begin work immediately on appropriate measures in a Security Council resolution," Tuesday's statement said.

North Korea said the test was merelyits "first response" to U.S. threats, and said it will continue with unspecified "second and third measures of greater intensity" if Washington maintains its hostility.

The strength of China's objection to the test may indicate a willingness to support stronger measures against North Korea, which depends on China for much of its foreign aid and basic materials such as fuel, experts said. China is a member of the U.N. Security Council.

Wu Qiang, with the Department of Political Science at Tsinghua University in Beijing, said China had publicly opposed the test earlier this month and under new its new leader, Xi Jinping, it may be less patient with the North.

"He may support South Korea, and decrease petrol, rice and trade aid in the future to apply sanctions," Wu said.

However, China will also consider the reactions from ordinary Chinese toward the nuclear test, Wu said.

China's foreign minister called North Korea's ambassador in to demand his country cease making further threats. Yang Jiechi delivered a "stern representation" to Ambassador Ji Jae Ryong and expressed China's "strong dissatisfaction and firm opposition" to Tuesday's test, the ministry said in a statement posted to its website.

"Yang Jiechi demanded that the Democratic People's Republic of Korea side cease talk that further escalates the situation and swiftly return to the correct channel of dialogue and negotiation," the statement said. 

President Obama on Tuesday called North Korea's third successful nuclear test a "highly provocative act" that "undermines regional stability" and threatens action by the international community. He said North Korea's nuclear program constitutes "a threat to U.S. national security."

The White House released the statement early Tuesday after North Korea detonated a miniaturized nuclear device at a northeastern test site, defying U.N. Security Council orders to shut down atomic activity or face more sanctions and international isolation.

U.N. Secretary-General Ban Ki Moon also condemned the test, saying it was "deplorable that Pyongyang defied the strong and unequivocal call from the international community to refrain from any further provocative measures."

South Korea's spy agency, the National Intelligence Service (NIS), warned that North Korea may conduct an additional nuclear test and launch a long-range missile if the U.N. moves to penalize it for its third nuclear test, the Yonhap news agency reported.

In a meeting with lawmakers belonging to the parliament's intelligence committee, the NIS said that it is too early to say the North has succeeded in weaponizing its nuclear technology, the news agency said..

Japanese Prime Minister Shinzo Abe called the test a "grave threat" that could not be tolerated. The Russian Foreign Ministry also condemned the North Korean test.

"We insist on North Korea putting an end to all illegal actions, complying to all U.N. Security Council orders, and fully giving up nuclear missile programs," Russia said in the official statement.

Russian Foreign Minister Sergei Lavrov, speaking to reporters in Pretoria, South Africa, said Moscow will continue efforts to get North Korea to participate in six-party talks "and we believe it is important to ensure its denuclearization."

"Increasing military tensions in the region is extremely dangerous," he said.

The six-party talks, which began in 2003, seek a peaceful solution to the security concerns raised by the North Korean nuclear weapons program. The talks include the United States, China, Russia, Japan, North Korea and South Korea. The talks followed passage of three U.N. resolutions that forbid the North from testing nuclear systems or transferring the technology to other states.

The United States has said it suspects North Korea has been sharing its progress with Iran, which is also accused of pursuing a nuclear weapon. The underground explosion could take North Korea a big step closer to its goal of building a nuclear warhead small enough to be mounted on a long-range missile that could threaten the United States.

Professor Yu Chung Sik, a political expert from South Korean teaching in Shanghai International Studies University, said there is little China will do in the end.

"China will pretend to be annoyed by North Korea's nuclear test again, but China has less impact on North Korea than before. In the end, China has to accept the reality, Yu said. "Although we are in tension now, I'm sure it will loosen in the future."

Chinese asked about the test said it was an example of how the two countries have drifted far apart.

"When I was young, I loved North Korean movies and songs and in my opinion, China and North Korea are good brothers, we fought American imperialism together and the relationship would last for 10,000 years," said Zhang Xuebin, 64, a retired worker living in Songzhuang. "Now I found it's not the case. China is developing fast; North Korea is still like the old times.

"If North Korea becomes more and more crazy, we may turn from friends into enemies someday."

Official state media said the test was conducted in a safe manner and is aimed at coping with "outrageous" U.S. hostility that "violently" undermines the North's peaceful, sovereign rights to launch satellites. North Korea faced sanctions after a December launch of a rocket the U.N. and Washington called a cover for a banned missile test.

The North said it used a "lighter, miniaturized atomic bomb" that still has more explosive force than past tests.

Monitoring stations in South Korea detected an earthquake in the North with a magnitude of 4.9 and the South's Defense Ministry said that corresponds to an estimated explosive yield of 6-7 kilotons. The United States Geological Survey said earlier Tuesday that it had detected a magnitude-4.9 earthquake.

"I was driving when the earthquake happened," said Zhang Binbo, a hotel owner Erdaobaihe township, Antu County in Jilin province.

"Many of my relatives called me to tell me they felt the house was a little shaking, which lasted for around one minute," he said. "I think North Korea is a little crazy.

"I wish China could give North Korea more pressure to ease the tension. We don't want any war or any dangerous weapon test anymore. Although the influence might be less than before, China still has a say in North Korea issue, I think," Zhang said.

The nuclear test is North Korea's first since leader Kim Jong Un took power in December 2011 following the death of his father, Kim Jong Il, and marks a bold statement for the young leader as he unveils his domestic and foreign policy for a country long estranged from the West.

Experts say regular tests are needed to perfect North Korea's goal of building nuclear warheads small enough to be placed on long-range missiles. This atomic test - North Korea's third since 2006 - is expected to take Pyongyang closer to possessing nuclear-tipped missiles designed to strike the United States.

China expressed firm opposition to the test but called for a calm response by all sides.