NATO Secretary General Jens Stoltenberg | Emmanuel Dunand/AFP via Getty Images NATO accuses Russia of violating nuclear treaty Ahead of defense ministers’ meeting, NATO Secretary-General Jens Stoltenberg demands Kremlin explain new missile.

Russia has a new type of missile that threatens Europe — in violation of a signature arms treaty — and NATO wants an immediate explanation, Secretary-General Jens Stoltenberg said Tuesday.

Speaking at a news conference ahead of a meeting of NATO defense ministers, Stoltenberg bluntly accused Russia of violating the 1987 Intermediate Range Nuclear Forces (INF) treaty, which banned an entire class of missiles that could be used by Russia to strike targets in Europe.

"Now, this treaty is in danger because of Russia’s actions," Stoltenberg said.

In a follow-up to Stoltenberg’s warning, the U.S. ambassador to NATO, Kay Bailey Hutchison, speaking at her own news conference, said the U.S. would give allies evidence of Russia’s violations and would be prepared to “take out” the Russian missiles if necessary.

It is unclear precisely what Hutchison meant, or if she intended to issue a threat that Moscow could view as highly provocative. Aides said they could not elaborate on her remarks or clarify them further.

"Russia has not provided any credible answers on this new missile" — NATO Secretary-General Jens Stoltenberg

The 1987 INF accord banned all missiles with a range between 500 and 5,500 kilometers, essentially offering a protective blanket to the European continent. It also banned American-made Pershing cruise missiles, which had been deployed by the U.S. and Germany and which Russia regarded as a severe threat.

Since 2014, the United States has accused Russia of violating the INF treaty, and Washington has imposed sanctions intended to pressure Russia into compliance. But amid other sanctions intended to punish Russia for its annexation of Crimea and military aggression in eastern Ukraine, the measures related to the INF apparently have not had any effect.

Stoltenberg, at his news conference, said that Russia had only recently admitted that it possesses a new type of ground-launched mid-range missile, called the 9M729 (also referred to as the SSC-8) which he said violates the INF.

"After years of denials, Russia recently acknowledged the existence of a new missile system called 9M729," Stoltenberg said at NATO headquarters. "Russia has not provided any credible answers on this new missile. The most plausible assessment would be that Russia is in violation of the treaty. It is therefore urgent that Russia addresses these concerns."

The Kremlin has denied violating the INF treaty, but has accused the U.S. of breaching the accord with a missile defense system deployed in Europe, including in Romania.

In a statement last December, the U.S. State Department called the INF treaty "a pillar of international security and stability."

Hutchison insisted the U.S. is committed to the accord, but threatened to abandon it and develop new mid-range weapons if Russia refuses to come back into compliance.

“The United States does not want to withdraw from the treaty; we certainly don't intend to violate the treaty,” Hutchison said.

“That is our goal: Russia in compliance,” Hutchison continued. “But if Russian continues to say they are not violating, while the evidence says that they are, then diplomacy needs to be strengthened and we need to look for other ways to bring Russia to the table on this issue.”

Trump has savagely criticized NATO allies, particularly Germany, which is one of the wealthiest NATO members, for not spending enough.

But in a pointed warning, she added: “There will come a point in the future where America will determine it has to move forward with a development phase that is not allowed by the treaty right now.”

Hutchison also said defense ministers would discuss pressing forward with the so-called 30-30-30-30 preparedness initiative, by which the alliance will aim to be able to counter Russian aggression or other threats by deploying 30 land battalions, 30 air squadrons, and 30 ships within 30 days.

The NATO defense ministers' meeting is the first gathering of senior allied officials since a disastrous leaders' summit last July, where U.S. President Donald Trump threatened to quit NATO if allies do not raise their military spending more quickly.

The allied defense ministers are expected to discuss the continued effort to bring national military spending to an agreed-upon target of 2 percent of GDP. Trump has savagely criticized NATO allies, particularly Germany, which is one of the wealthiest NATO members, for not spending enough. Germany has said it is aiming to increase its military spending to 1.5 percent by 2024, still short of the 2 percent target.

At this week's meeting, ministers are also expected to discuss recent developments in Macedonia, where a referendum on Sunday to end the country's name dispute with Greece — a crucial step toward Macedonia potentially joining NATO — failed to achieve the legal threshold of 50 percent voter turnout, even though more than 90 percent of those who voted supported the name-change plan.

Defense ministers will also discuss NATO partnership efforts with Georgia, which has struggled with two breakaway regions, Abkhazia and South Ossetia, which are under Russian control and protection.