"As concerning as this launch was, we did not deem it a threat to homeland," said White House national security spokesman John Kirby.

However, Kirby expressed strong concern about Pyongyang's surge in test launches of short and long-range missiles that have the potential to carry nuclear warheads.

"Every single time they launch, they learn. That's concerning. Even if the launch is a failure or only partially successful, they still learn," Kirby told reporters.

"That's destabilizing, not just to the peninsula but to the region itself," he said.

The United States has repeatedly offered talks with North Korea over its denuclearizing the Korean peninsula without preconditions, he said.

Still, Kirby added, the United States as well as South Korea and Japan were "working very hard to make sure we have in place adequate defensive capabilities.