NATO Secretary-General Jens Stoltenberg said Tuesday that there is every indication that Russia is planning a "full-scale attack" on Ukraine and urged Moscow to reverse course immediately.

"We urge Russia in the strongest possible terms to choose the path of diplomacy. This is the most dangerous moment in European security for a generation," Stoltenberg told reporters from Brussels. 

"Every indication is that Russia continues to plan for a full-scale attack on Ukraine," he warned.

WHITE HOUSE DECLARES RUSSIAN INVASION IN UKRAINE

NATO Secretary General Jens Stoltenberg speaks to media during the Munich Security Conference in Munich, Germany, Saturday, Feb. 19, 2022. 

NATO Secretary General Jens Stoltenberg speaks to media during the Munich Security Conference in Munich, Germany, Saturday, Feb. 19, 2022.  (AP Photo/Michael Probst)

The secretary-general’s comments come just one day after Russian President Vladimir Putin first announced his decision to recognize the independence of two Russian-backed breakaway regions in eastern Ukraine, and then ordered "peacekeeping" troops into the Donbas region. 

Stoltenberg confirmed that NATO had "evidence" that Russian forces have already invaded Ukraine following Putin’s order. 

Over 150,000 troops have amassed along Ukraine’s border in Russia, Belarus as well as in occupied Crimea and Donbas. 

"Moscow has now moved from covert attempts to destabilize Ukraine to overt military action," the NATO chief said. "Many units are forward-deployed in combat formations. They are out of their camps in the field and ready to strike."

Stoltenberg applauded immediate moves by nations like Germany, the U.K. and the U.S. to target financial institutions tied to the Kremlin and said NATO will continue to help defend Ukraine by providing military equipment and "sustained financial support."

A Ukrainian serviceman stands in an observation point near the frontline village of Krymske, Luhansk region, in eastern Ukraine, Saturday, Feb. 19, 2022. 

A Ukrainian serviceman stands in an observation point near the frontline village of Krymske, Luhansk region, in eastern Ukraine, Saturday, Feb. 19, 2022.  (AP Photo/Vadim Ghirda)


RUSSIAN TROOPS MOVED INTO EASTERN UKRAINE'S BREAKAWAY REGIONS, EUROPEAN OFFICIALS SAY

The U.S. and NATO have said they will not deploy forces to Kyiv to engage with Russia militarily as Ukraine is not a NATO member.

Member nations surrounding Ukraine like Romania and Poland have received military support as thousands of troops have been deployed from the U.S., U.K. and Baltic states to protect against any possible Russian aggression. 

In answer to a reporter’s questions on mounting concerns that there will be a "full-on war" in Europe, Stoltenberg warned, "There is a real risk."

"Ukraine is a highly valued partner, we support them with military support, with political support," he said. "But when it comes to NATO allies we provide absolute security guarantees. Meaning we make it absolutely clear that an attack on one ally will trigger a response from the whole alliance – one for all, all for one.

"There is no room for miscalculation about our ability to defend all allies," Stoltenberg added.

U.S. Army soldiers from the 18th Airborne Division board a C-17 aircraft as they deploy to Europe, Thursday, Feb. 3, 2022 from Fort Bragg, North Carolina. 

U.S. Army soldiers from the 18th Airborne Division board a C-17 aircraft as they deploy to Europe, Thursday, Feb. 3, 2022 from Fort Bragg, North Carolina.  (AP Photo/Chris Seward)

CLICK HERE TO GET THE FOX NEWS APP

The NATO head said it is still possible for Russia to reverse course by not further invading Ukraine and come back to the negotiating table. 

"It’s never too late to not attack and that’s the reason why we continue to call on Russia to step back, to de-escalate and to engage in good faith in diplomatic efforts," Stoltenberg said.