By Ryan Browne and Elise Labott @ CNN, Updated 9:03 PM ET, April 20

Washington -- Chinese air force land-attack, cruise-missile-capable bombers were put "on high alert" on Wednesday as the US sees evidence that the Chinese military is preparing to respond to a potential situation in North Korea, a US defense official tells CNN.

The official said the US has also seen an extraordinary number of Chinese military aircraft being brought up to full readiness through intensified maintenance. These recent steps by the Chinese are assessed as part of an effort to "reduce the time to react to a North Korea contingency," the official said.

Such a contingency could include the risk of of an armed conflict breaking out as tensions on the peninsula have increased in the wake of multiple North Korean missile tests [....]

[....]  Trump told a news conference "some very unusual moves have been made over the last two or three hours," and that he was confident Chinese President Xi Jinping would "try very hard" to pressure Beijing's ally and neighbor North Korea over its nuclear and missile programs [.....]