On Monday, the US re-designated North Korea as a "state sponsor of terrorism" – the latest expansion of the Trump administration's diplomatic arsenal against the nuclear ambitions of the Kim regime.

While putting Pyongyang on the terrorism blacklist turns up the pressure politically, experts have seen the move as heavy on symbolism and light on impact. North Korea already faces considerable international isolation from a combination of US and UN-imposed sanctions prohibiting trade and financial transactions.

Speaking to reporters on Monday after President Donald Trump announced the measure, US Secretary of State Rex Tillerson said the decision was "very symbolic" and that the practical effects "may be limited" but would hopefully "close off a few loopholes."

But the designation of North Korea as a state sponsor of terror is only window dressing for what President Trump calls a "maximum pressure campaign" against Pyongyang. In his announcement Monday, Trump said multiple actions are to be rolled out over the next two weeks, culminating in the "highest level" of sanctions ever seen.

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New US sanctions

On Tuesday, the US Treasury Department began to tighten the screws, issuing a new round of sanctions on numerous Chinese and North Korean businesses and individuals that Washington has accused of engaging in trade of goods with North Korea "cumulatively worth hundreds of millions of dollars."

The Chinese companies targeted by the sanctions are all located in the Dandong region on the North Korean border. According to the Associated Press, the goods that were traded in violation included notebook computers, coal, iron and other raw materials. The US has focused on this area in the past as it has the potential to draw Chinese entities eager to do business with North Korea.

The US also sanctioned North Korea's Maritime Administration, transport ministry and sectors of the shipping industry. The US alleges that North Korea has been engaging in deceptive shipping practices to get embargoed goods into the country.

On Wednesday, China's Foreign Ministry spokesman Lu Lang told a regular press briefing in Beijing, that China opposed unilateral sanctions and "the wrong method of exercising long-arm jurisdiction." Lu also said that Washington should provide "solid evidence" of UN sanctions violations and that China would "severely deal with that in accordance with our laws and regulations."

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China insists it has been implementing the sanctions imposed in September by the UN Security Council that prohibit importing and exporting North Korean goods and doing business with North Korean entities.

"The sanctions on the Chinese trading companies send a message directly to companies in China that there will be consequences for trading with North Korea," said Peter Harrell, a former US State Department official and sanctions expert at the Center for New American Security, a defense think-tank in Washington.

"I think that those sanctions are likely to have a more significant economic impact than the state sponsor of terrorism designation," he told DW.

US sanctions bar individuals and organizations in the targeted country from holding US assets or doing business with Americans and penalize third parties who engage in trade or business.

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Reaction from Pyongyang

On Wednesday, North Korea condemned the terrorist designation as a "serious provocation" and reiterated that sanctions would never cause the regime to give up its nuclear weapons program, which it sees as a deterrent essential for its survival.

"Our army and people are full of rage and anger towards the heinous gangsters who dared to put the name of our sacred country in this wretched list of 'terrorism'," a spokesperson told North Korea's official news agency KCNA. The statement added that the decision was "clearly a mockery of world peace and security."

The KCNA report also said that the US is "kingpin of all kinds of terrorism that cannot prevent terror in its own territory" and is acting like an "international judge on terrorism."

After the last round of UN sanctions were issued against Pyongyang in September in response to its sixth and largest nuclear test, North Korea responded defiantly by firing a missile over Japan. Media reports from South Korea in recent days indicate some experts are concerned the latest volley of US sanctions will similarly increase tensions on the Korean Peninsula.

"Whether the new sanctions will increase tensions on the Korean peninsula is really in North Korea's hands," said Harrell. "Clearly, if North Korea responds to the state sponsor of terrorism designation with a new missile or nuclear test, that will escalate tensions," he said, adding that the US and its international partners should not let the threat of new tests deter the "economic pressure campaign" against Pyongyang.

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The end of diplomacy?

Another area of concern is if the US terror blacklisting North Korea effectively closes the door on a diplomatic solution to stopping North Korea from further developing nuclear weapons.

US officials maintain that if North Korea is willing to stop its development program and disarm, then steps toward normalizing relations could be possible. Washington says North Korea is close to possessing a nuclear armed missile that could threaten the US and its allies.

Pyongyang has shown no interest in talks that would lead to abandoning its nuclear weapons development.

"For the last year I've advocated a 'more pressure, more diplomacy' strategy that would move more economic pressure in parallel with more aggressive bids for diplomatic talks, rather than the current 'sequenced' approach in which we push pressure for a year or two and then start talks," said Harrell.

"While I am skeptical that talks would yield any results in the near term, I have long been a believer that we should keep lines of communication open, even while simultaneously increasing economic pressure," he said, adding that he was not optimistic about the chances for a diplomatic solution, given the sharp rhetorical exchanges between Washington and Pyongyang.

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What is a state sponsor of terror?

The US designation of a "state sponsor of terrorism" was begun in 1979 and originally listed Iraq, Libya and South Yemen. As of Monday, it lists North Korea, Iran, Syria and Sudan.

According to the US State Department, "To designate a country as a State Sponsor of Terrorism, the Secretary of State must determine that the government of such country has repeatedly provided support for acts of international terrorism."

North Korea was first put on the state sponsor of terrorism list in 1988, after North Korean agents planted a bomb on a South Korean airliner in 1987, which killed everyone on board. In 2008, the US under President George W. Bush removed North Korea from the list as part of a failed diplomatic effort to get Pyongyang to stop its development of nuclear weapons.

"It is not a surprising development. The political basis for lifting the previous designation evaporated when the DPRK reneged on the agreement it made with the Bush Administration about its nuclear and missile programs," Joseph DeThomas, a contributor to the 38 North think tank at Johns Hopkins University in Washington, told DW.

In announcing the decision on Monday, President Trump said that North Korea threatened the world with "nuclear devastation" and "repeatedly supported acts of international terrorism, including assassinations on foreign soil" - referring to the suspected assassination earlier this year of Kim Jong Un's half-brother, Kim Jong Nam, in Kuala Lampur.

"The technical justification [of removing North Korea from the list] was called into question when DPRK agents assassinated Kim Jong Nam," said DeThomas.

Trump also mentioned Otto Warmbier, an American student held in North Korean captivity for over 500 days before being returned to the US in a vegetative state and dying shortly thereafter.

On timing of the designation, US Secretary of State Tillerson said Monday that the State Department has gone through a lengthy process to establish that North Korea met the criteria for a state sponsor of terrorism.

"The North Korean regime must be lawful, it must end its unlawful nuclear ballistic missile development and cease all support for international terrorism - which it is not doing," said Trump.