Breaking News Emails

Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.
 / Updated  / Source: Reuters

The U.S. military staged bombing drills with South Korea over the Korean peninsula and Russia and China began naval exercises ahead of a U.N. General Assembly meeting on Tuesday where North Korea's nuclear threat is likely to loom large.

The flurry of military drills came after Pyongyang fired another mid-range ballistic missile over Japan on Friday and the reclusive North conducted its sixth and most powerful nuclear test on Sept. 3 in defiance of United Nations sanctions and other international pressure.

U.S. Air Force B-1B Lancer bombers fly with F-35B fighter jets and South Korean Air Force F-15K fighter jets on Monday.South Korean Defense Ministry via Getty Images

A pair of U.S. B-1B bombers and four F-35 jets flew from Guam and Japan and joined four South Korean F-15K fighters in the latest drill, South Korea's defense ministry said.

The joint drills were being conducted "two to three times a month these days," Defense Minister Song Young-moo told a parliamentary hearing on Monday.

In Beijing, the official Xinhua news agency said China and Russia began naval drills off the Russian far eastern port of Vladivostok, not far from the Russia-North Korea border.

Those drills were being conducted between Peter the Great Bay, near Vladivostok, and the southern part of the Sea of Okhotsk, to the north of Japan, it said.

Related: Trump Calls Kim Jong Un 'Rocket Man'

The drills are the second part of China-Russian naval exercises this year, the first part of which was staged in the Baltic in July. Xinhua did not directly link the drills to current tension over North Korea.

China and Russia have repeatedly called for a peaceful solution and talks to resolve the issue.

On Sunday, however, Ambassador to the United Nations Nikki Haley said the U.N. Security Council had run out of options on containing North Korea's nuclear program and the United States might have to turn the matter over to the Pentagon.

Related: How Trump Administration Has Handled the N. Korea Crisis

President Donald Trump has vowed that North Korea will never be able to threaten the United States with a nuclear-tipped ballistic missile.

Asked about Trump's warning last month that the North Korean threat to the United States would be met with "fire and fury," Haley said: "It was not an empty threat."

Washington has also asked China to do more to rein in its neighbor and ally, while Beijing has urged the United States to refrain from making threats against the North.

A bomb hits a mock target at the Pilseung Firing Range in Gangwon-do, South Korea, during an exercise on Monday.South Korean Defense Ministry via Getty Images

The international community must remain united and enforce sanctions against North Korea after its repeated launch of ballistic missiles, Japanese Prime Minister Shinto Abe said in an editorial in the New York Times on Sunday.

Such tests were in violation of Security Council resolutions and showed that North Korea could now target the United States or Europe, he wrote.

Abe also said diplomacy and dialogue would not work with North Korea and concerted pressure by the entire international community was essential to tackle the threats posed by the north and its leader, Kim Jong Un.

Pyongyang has launched dozens of missiles as it accelerates a weapons program designed to provide the ability to target the United States with a powerful, nuclear-tipped missile.

It says such programs are needed as a deterrent against invasion by the United States, which has 28,500 troops stationed in South Korea. On Saturday, it said it aimed to reach an "equilibrium" of military force with the United States.

The United States and South Korea are technically still at war with North Korea because the 1950-53 Korean conflict ended with a truce and not a peace treaty.