China’s exports to North Korea jumped an annual 20.9 percent in the first three quarters of 2017, customs data showed.

From January to September, Asia’s largest economy exported $2.55 billion in value to the pariah state, the data showed, according to Reuters. Imports from North Korea during that nine-month period actually fell 16.7 percent, according to the data, and so the total trade figure only saw a 3.7 percent increase, Reuters said.

Of note, both exports and imports between the two nations fell in September from the previous month, according to the data: Exports to North Korea sank from $315.97 million to $266.35 million, and imports from North Korea fell from $288.29 million to $145.82 million.

The figures come as much of the world, including the United Nations, calls for tight economic sanctions on the rogue nation. The government in Pyongyang is paying for a rapidly expanding nuclear weapons program, and it has verbally threatened several countries with attack.

Last month, Beijing announced its intention to restrict trade with Pyongyang on several key items, including textiles, seafood and petroleum products, in compliance with international sanctions. Chinese President Xi Jinping’s administration has also banned mainland lenders from doing business with North Korean clients.

President Donald Trump is expected to pressure Xi to do more to contain the North when the two leaders meet in Beijing next month.

North Korean ruler Kim Jong Un has been engaged in a tense war of words with Trump in recent months, which has stoked fears of military action on the Korean Peninsula. Last week, a U.S. nuclear-powered aircraft carrier conducted drills with South Korea’s navy in an exercise aimed at showing off Washington’s defense capabilities.

—Reuters contributed to this report.