Vice President Mike Pence called North Korea’s latest missile test a “provocation,” and Sen. John McCain noted that even though it was a failure, the Pyongyang learns something new with every launch.

The comments came as the New York Times reported the U.S. has been conducting a covert cyberwar to thwart the North’s missile program.

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North Korea fired a ballistic missile early Sunday from its Sinpo submarine base, but it blew up almost immediately. The test followed last week’s military parade in which the North showed off what appeared to be missiles capable of carrying multiple warheads and big enough to reach the United States.

“This morning’s provocation from the North is just the latest reminder of the risks each one of you face each and every day in the defense of the freedom of the people of South Korea and the defense of America in this part of the world,” Pence said during an Easter dinner at Yongsan military base in Seoul at the start of his 10-day tour of Asia. Pence also pledged the U.S. will continue to support its alliance with South Korea.

National Security Adviser H.R. McMaster echoed Pence’s remarks in an interview on ABC’s “This Week,” calling the missile test part of a pattern of “provocative and destabilizing and threatening behavior.” He said there now is an “international consensus … that this is a situation that just can’t continue.”

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Sen. Bernie Sanders, I-Vt., said on CNN’s “State of the Union” the Trump administration needs to develop a coherent strategy and must not act unilaterally. President Donald Trump has talked with Chinese President Xi Jinping about North Korea’s missile and nuclear programs both at a face-to-face summit at Mar-a-Lago and by phone. Sanders said China needs to be pressed to rein in Pyongyang because “comprehensive” agreements that have been negotiated in the past did little to dissuade the Hermit Kingdom.

McCain, R-Ariz., the head of the Armed Services Committee called China “the key” in stopping Kim Jong Un because of its control over North Korea’s economy.

“China can shut them down and we should be … we should expect them to act to prevent what could be a cataclysmic event,” McCain said on NBC’s “Meet the Press.” McCain noted that the North has “made steady progress while we have made agreement after agreement after agreement” in the past two decades, no mater whether a Republican or Democrat was in the White House.

“This guy in North Korea is not rational. His father and his grandfather were much more rational than he is,” said McCain, who has described Kim as a “crazy fat kid.”

The Times reported former President Barack Obama ordered a surge in electronic warfare against Pyongyang to try to cripple the missile program. Since it was initiated, the missile failure rate has increased but it was unclear whether any individual failure was the result of that sabotage.