Operation "Spider's Web" Launched: Escalation to follow? VIDEO

The operation, launched by the Security Service of Ukraine (SBU), reportedly targeted four airfields deep inside Russian territory, hitting 41 aircraft and causing what Kyiv claimed was $7 billion in damage.

The targeted air bases were reportedly home to Tu-95 and Tu-22M3 bombers, key carriers of long-range cruise missiles used by Moscow in airstrikes against Ukrainian cities.

"I'm telling you the risk levels are going up. When you attack part of an adversary's national survivability system, which is their nuclear triad, that means the risk level goes up because you don't know what the other side is going to do," Kellogg said.

• The Russians struck Ukraine: In an hour and a half they destroyed everything PHOTO/VIDEO

According to the SBU, 117 drones were launched from mobile platforms across Russia, enabling simultaneous strikes on targets located thousands of kilometers from Ukraine's borders.

Kellogg also pointed to reports of explosions at the Severomorsk naval base, home to some of Russia's most advanced submarines. Kyiv has not confirmed that it targeted Russia's Northern Fleet.

"What really worried me was the fact that there were reports that they attacked the naval, Northern Fleet headquarters in Severomorsk," Kellogg said.

"And if that's the case – when you're attacking two legs of the triad – it's very clear that the risk levels are going to increase."

The Russians denied that the base was hit

Russian officials have denied the base was hit, and no independent confirmation has emerged.

According to Kellogg, the attacks showed that Kyiv "isn't lying about it".

"Ukraine is basically saying, 'We can play this game, too.' And they can raise the level of risk to levels that are essentially, in my opinion, unacceptable," he added.

Despite the scale and strategic implications of the Ukrainian operation, Russian President Vladimir Putin has not publicly commented on the strike. US President Donald Trump, who has positioned himself as a peacemaker, also remained mute.

Pressed by reporters, White House spokeswoman Karoline Lewitt confirmed that Trump had not been informed in advance of the operation.

"I would like the president to speak about it himself. The president does not want this war to continue. He wants this war to stop," Lewitt said.

Ukrainian officials say the operation took 18 months to plan. While Kyiv claims the strike dealt a serious blow to Russia's strategic air capabilities, the full extent of the damage remains unverified.

Operation Spider's Web marks one of Ukraine's most sophisticated and far-reaching operations since the start of the full-scale war in 2022 – and a clear signal of Ukraine's growing ability to strike deep inside Russian territory.