WASHINGTON, D.C. — President Obama issued an executive order imposing “robust new sanctions on North Korea” in retaliation for its “illicit” nuclear activities, rocket tests, and satellite launch.

On Thursday, China expressed opposition to unilateral sanctions against North Korea, arguing that such a move may raise tension.

“The new [US] sanctions threaten to ban from the global financial system anyone who does business with broad swaths of North Korea’s economy, including its financial, mining and transport sectors,” reports Reuters.

“The so-called secondary sanctions will compel banks to freeze the assets of anyone who breaks the blockade, potentially squeezing out North Korea’s business ties, including those with China,” it adds.

BBC points out that President Obama’s executive order includes measures from the sanctions recently agreed by the United Nations Security Council, considered the harshest sanctions in decades against North Korea.

It also contains separate sanctions approved by Congress and enacted by Obama in February.

North Korea’s January 6 nuclear test and February 7 satellite launch violated existing UN curbs on the isolated country.

“The US and the global community will not tolerate North Korea’s illicit nuclear and ballistic missile activities, and we will continue to impose costs on North Korea until it comes into compliance with its international obligations,” said White House spokesman Josh Earnest in a statement announcing the new sanctions on North Korea.

“The order is not targeted at the people of North Korea, but rather is aimed at the Government of North Korea and its activities that threaten the United States and others,” noted Obama in a message to Congress.

Although China is North Korea’s only major ally, it disapproves of its nuclear program and has called for the Korean peninsula to be free of atomic weapons.

China has signed up for tough new UN sanctions against North Korea, but it has stressed that sanctions are not the answer and that only a resumption of negotiations can resolve the dispute over North Korea’s nuclear program.

When asked whether China was concerned the U.S. sanctions could impact “normal” business relations between Chinese banks and North Korea, Foreign Ministry spokesman Lu Kang said this was something China was “paying attention to.”

“First, as I’ve said many times before, China always opposes any country imposing unilateral sanctions,” Lu told reporters in Beijing, according to Reuters.

Lu added:

Second, under the present situation where the situation on the Korean Peninsula is complex and sensitive, we oppose any moves that may further worsen tensions there. Third, we have clearly stressed many times in meetings with the relevant county, any so-called unilateral sanctions imposed by any country should neither affect nor harm China’s reasonable interests.

Amid the heightened tensions, North Korea sentenced Otto Warmbier, a 21-year-old American student, to 15 years of hard labor on Wednesday for “severe crimes” against the state.

The United States demanded that North Korea immediately release the U.S. student, who, Reuters reports, “was arrested for trying to steal a propaganda sign from a hotel while on a visit in January.”

This month, the U.S. and South Korea are expected to hold their annual military drills, which tend to generate tension. North Korea has threatened this year to launch “a pre-emptive nuclear strike of justice” against the U.S. and South Korea.