Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

Two U.S. B-1B bombers flew over South Korea in a show of force following North Korea’s second test launch of an intercontinental ballistic missile, the U.S. military said.

Pacific Air Forces commander Gen. Terrence J. O'Shaughnessy said in a statement Saturday night ET that "North Korea remains the most urgent threat to regional stability."

"Diplomacy remains the lead; however, we have a responsibility to our allies and our nation to showcase our unwavering commitment while planning for the worst-case scenario," O'Shaughnessy said. "If called upon, we are ready to respond with rapid, lethal, and overwhelming force at a time and place of our choosing."

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

North Korea on Friday launched an ICBM that traveled around 1,000 km, or around 621 miles, before crashing into the Sea of Japan, also known as the East Sea, the U.S. military said.

A South Korean military official said the missile’s estimated firing range has increased since the first launch, and the Union of Concerned Scientists estimated that based on available information about the missile test's trajectory a missile could "easily reach the U.S. West Coast and a number of major U.S. cities."

North Korea has conducted five nuclear tests since 2006, including two last year. It conducted its first ICBM test earlier this month.

The B-1 bombers took off from Guam and flew to Japanese airspace, where they were joined by Japanese F-2 fighter jets, the U.S. Pacific Air Forces said.

The U.S. bombers then flew over South Korean airspace and were joined by South Korean jets, and the U.S. bombers performed a low pass over Osan Air Base before returning to Guam, according to the Pacific Air Forces.

A handout photo made available by the U.S. Department of Defense shows a B-1B Lancer receiving fuel from a KC-135 Stratotanker during a 10-hour mission from Andersen Air Force Base, Guam, into Japanese airspace and over the Korean Peninsula, July 30, 2017. US AIR FORCE/STAFF SGT. JOSHUA S / EPA

The military said the flight was in direct response to the two ICBM tests. The aircrews "practiced intercept and formation training" during the 10-hour mission. Two U.S. B-1 bombers also conducted an attack exercise in South Korea after the first ICBM test.

President Donald Trump tweeted Saturday that he was "very disappointed" with China and seemed to accuse that country of doing little to rein in North Korea. China is an ally and key trading partner of North Korea.

Trump said of China "they do NOTHING for us with North Korea, just talk. We will no longer allow this to continue. China could easily solve this problem!"

I am very disappointed in China. Our foolish past leaders have allowed them to make hundreds of billions of dollars a year in trade, yet... — Donald J. Trump (@realDonaldTrump) July 29, 2017

...they do NOTHING for us with North Korea, just talk. We will no longer allow this to continue. China could easily solve this problem! — Donald J. Trump (@realDonaldTrump) July 29, 2017

After Friday’s missile test, U.S. Secretary of State Rex Tillerson said in a statement that the United States will never accept a nuclear-armed North Korea.