Members of the United Nations Security Council are locked in a bitter dispute over North Korea. The US is blaming Pyongyang's allies for tacitly condoning recent missile launches. But China and Russia say leaders in Washington are stoking tensions on the peninsula.

Military personnel from the US and South Korea have been holding joint exercises since Monday. They just announced that they are extending the drills to Saturday.

North Korean officials say that such a "sustained provocation" is bound to be met with a "sustained counter-action."

The US ambassador to the UN told Security Council members on Friday that the North has fired 59 missiles this year alone. Linda Thomas -Greenfield blamed China and Russia for providing Pyongyang with "blanket protection." She said those members have "bent over backwards" to justify the North's repeated violations and, in turn, have "enabled the country and made a mockery of this Council."

Delegates from South Korea and Japan were invited to attend. They, too, criticized China and Russia for "emboldening" the North.

China's ambassador shot back. Zhang Jun said the "root causes" of the launches did not occur in "isolation." He called on the US to stop "unilateral declarations of tense confrontation" and instead show sincerity by "acting responsibly."

The Russian delegate echoed that criticism. Anna Evstigneeva said US leaders are using sanctions to try to force North Korea into "unilateral disarmament."