Pressure grew on President Barack Obama on Friday — including from his own party's nominee, Hillary Clinton — to take more aggressive action against North Korea for its latest nuclear weapons test, including using new sanctions authority that could put the White House at odds with China, Pyongyang's protector and largest trading partner.

The fifth and largest underground test, which came on the heels of three provocative missile tests, stoked new fears that North Korea’s boasts that it can place a hydrogen bomb atop long-range missiles may soon be reality.


Members of Congress in both parties condemned the regime's latest flouting of United Nations resolutions that prohibit its nuclear and missile programs. But a number of leading Republicans also accused Obama of being soft on Chinese companies, banks, and individuals doing business with North Korea who they said could be sanctioned under a law passed in February.

Obama "should immediately make full use of the sanctions authorities Congress gave him earlier this year," House Speaker Paul Ryan said in a statement, "and he should join me in urging China, as Pyongyang’s chief sponsor, to fully enforce the international sanctions on the Kim regime."

Clinton called the test "outrageous and unacceptable" in a statement of her own, describing North Korea's "determination to develop a deliverable nuclear weapon" as a "direct threat to the United States." The former secretary of state also urged the U.S. to "make sure" China will "meaningfully increase pressure on North Korea."

In a further effort to distance herself from current policy, Clinton also called for a "rethinking" of America's strategy toward North Korea during a news conference in New York. Sanctions are "not enough," she said, proposing an "urgent effort" to pressure Beijing into cracking down on Pyongyang.

Republican presidential nominee Donald Trump only briefly mentioned North Korea in his speech to religious voters on Friday afternoon, but his campaign issued a statement blaming Clinton for the nuclear test. North Korea's action, Trump communications aide Jason Miller said, “is yet one more example of Hillary Clinton's catastrophic failures as secretary of state. Clinton promised to work to end North Korea’s nuclear program as secretary of state, yet the program has only grown in strength and sophistication."

But much of the discussion in Washington focused on the North Korea Sanctions and Policy Enhancement Act. Passed by Congress and signed by Obama earlier this year, it gives the Obama administration, among other things, new authority to sanction any individual who "imports, exports, or re-exports luxury goods to or into North Korea" or "engages in money laundering, counterfeiting of goods or currency, bulk cash smuggling, or narcotics trafficking that supports the government of North Korea or its senior officials."

Rep. Ed Royce (R-Calif.), who chairs the House Foreign Affairs Committee and led the push for more sanctions authority, said Obama’s policies are “falling short” by not imposing sanctions on Chinese companies and banks.

Royce referenced a leaked U.N. report that accused China of lax enforcement and "cites evidence that Pyongyang moved tens of millions of dollars through a Singaporean branch of China’s biggest bank to evade sanctions," according to a report in Foreign Policy magazine. The report found that North Korea "has been effective in evading sanctions and continues to use the international financial system, airlines and container shipping routes to trade in prohibited items."

For years, notoriously bombastic North Korea has threatened a nuclear missile attack on the United States, proclaiming that if one of its nuclear bombs "were to be mounted on an intercontinental ballistic missile and fall on Manhattan in New York City, all the people there would be killed immediately and the city would burn down to ashes."

And for years, U.S. intelligence officials and nuclear proliferation specialists have mostly rolled their eyes. Not so anymore. The Friday test, which registered 5.3 in seismic magnitude and was immediately picked up by the international network established to monitor nuclear tests under the Comprehensive Test Ban Treaty, was believed to be about 10 kilotons, or equal to the bombs dropped by the United States on Hiroshima and Nagasaki to end World War II in 1945.

Coming after a series of increasingly advanced missile tests — including one that launched a satellite into orbit in February — it has ratcheted up the alarm that the regime may in fact be able to deliver a nuclear weapon, as it has repeatedly threatened.

"If it hasn't already miniaturized, it will do soon," said James Acton, a nuclear expert at the Carnegie Endowment for International Peace. "If it cannot yet threaten its neighbors, it will be able to soon. And it will eventually be able to strike the United States."

Obama addressed the gravity of threat in a sober statement on Friday that spoke to his "responsibility" for leading the effort to contain the North Korean threat.

"Today's test, North Korea's second this year, follows an unprecedented campaign of ballistic missile launches, which North Korea claims are intended to serve as delivery vehicles for nuclear weapons targeting the United States and our allies, the Republic of Korea and Japan," he added. "As commander in chief, I have a responsibility to safeguard the American people and ensure that the United States is leading the international community in responding to this threat and North Korea's other provocations with commensurate resolve and condemnation."

He also vowed to work with the "the international community to vigorously implement existing measures imposed in previous resolutions, and to take additional significant steps, including new sanctions, to demonstrate to North Korea that there are consequences to its unlawful and dangerous actions."

And he re-committed to deploying a new missile anti-missile system, known as Theater High Altitude Area Defense, to help defend South Korea and other neighboring allies.

Yet a key member of the international coalition that has tried to reign in North Korea's nuclear and missile programs is China, which is still doing business with its communist neighbor.

The Obama administration has so far not used all the sanctioning authorities that might target those activities -- and last week at an economic summit in Laos, Obama defended China's record in punishing North Korea economically for its destabilizing behavior.

"I can tell you that based on not only their presentations but actually intelligence and evidence that we've seen, China has done more on sanctions implementation than they have on some of the previous U.N. Security Council sanctions," Obama said at ASEAN meeting when asked about China's dealings with North Korea. "But you are absolutely right that there are still places where they need to tighten up. And we continue to indicate to them the importance of tightening those up."

Numerous Republicans on Friday called on the administration to use the authorities.

Texas Sen. Ted Cruz urged sanctions on "Chinese entities responsible for aiding in the DPRK’s proliferation activities,” referring to the North Korean regime, formally the Democratic People's Republic of Korea, by its acronym.

"Tough talk from the Obama administration is not enough — we need rigorous enforcement of sanctions, especially against Chinese entities that continue to engage in prohibited activities with North Korea," added Sen. Kelly Ayotte of New Hampshire, another member of the Armed Services Committee.

But some experts on North Korea doubted that more sanctions will make much of a difference.

"They have squeezed and squeezed and squeezed and it hasn't done much," said David Wright, co-director of the global security program at the Union of Concerned Scientists. "Maybe if they could get China to do more it would make a difference. But there is a long border up there where there is a lot of trade."

What is clearer to Wright is that despite the international pressure, North Korea is closer than ever to being able to blackmail its neighbors. Pyongyang could brandish its short-range Scuds and No Dong missiles, which can carry a payload weighing up to 700 kilograms. "There is nothing fundamental that would keep them from doing that," he said.

But Wright doubts that North Korea is anywhere near being able to launch a nuclear strike on the United States.

"We have not seen them test a re-entry shield for a long-range missile," he said. "But for the closer neighbors it is a different issue."