With President Trump’s visit looming on the horizon, and North Korea’s less than agreeable behavior on the top of the list of things to talk about, Beijing has banned Chinese tourism to the communist hermit kingdom.

According to Reuters, Chinese tour operators on the border city of Dandong were informed on Tuesday that travel to North Korea’s capital city of Pyongyang, and other areas must suddenly cease, much to their surprise:

“It was very unexpected, we had no idea this was going to happen until we received the notification today,” said a Chinese tour operator who runs trips to North Korea out of Dandong “This is devastating news for us,” he said, adding the order had come from the Dandong Tourism Bureau.

While this tourism ban might not seem like much, it’s a huge slap in the face to North Korea. For one, China is supposed to be its primary ally, and this tourism ban may be a solid sign of Beijing choosing Washington over Pyongyang.

But secondly is the fact that one of North Korea’s primary modes of income is tourism from China. With U.N. sanctions on North Korea prohibiting exports from coal to seafood, Pyongyang is hard up for cash. This travel ban will be another deduction from an already shallow coffer.

While China has prohibited travel to Pyongyang, it still allows travel to Sinuiju, the North Korean city opposite Dandong, which is popular for Chinese tourists looking to take a short day trip.

According to Reuters, 237,000 Chinese visited in 2012, but China stopped publishing the statistics in 2013.

This will be another Chinese kick to North Korea’s head as China has participated in various U.N. sanctions against North Korea due to the latter’s inability to halt its nuclear missile development program. North Korea’s actions have been overtly antagonistic, causing the U.S. to become naturally angry and defensive.

This has then caused the U.S. to put pressure on China to rein North Korea in, which China has capitulated to on more than one occasion. This has caused a rift to develop between the two nations, with Kim Jong Un and Xi Jinping privately insulting one another.

As China is trying to improve it’s standing on the world stage as a business leader, North Korea’s continued misbehavior stands in the way of China’s progress. With this travel ban, Xi Jinping may be attempting to show the U.S. that it’s ready to be far more friendly with it than its souring ally.