The United States will in the coming days lay out its planned "next steps" in the tense standoff with Russia, after intense diplomacy failed to ease the threat of a new conflict over Ukraine, a senior official said Sunday.
Amid mounting fears of a Russian invasion of Ukraine, national security advisor Jake Sullivan said the US was "ready either way."
"We're in close touch with our allies and partners, including the Ukrainians," the top advisor to President Joe Biden told CBS. "We're coordinating closely on next steps. And we'll have more to share in terms of the next steps into the diplomacy early next week."
"But the key point here is that we're ready either way. If Russia wants to move forward with diplomacy, we are absolutely ready to do that in lockstep with our allies and partners.
"If Russia wants to go down the path of invasion and escalation, we're ready for that too, with a robust response."
Washington says Russia has massed nearly 100,000 troops along the border with Ukraine and has accused Moscow of wanting to create a "pretext" for a possible offensive.
The Kremlin again insisted on Sunday that it did not want to lead "a military action," even while warning of unnamed "counteractions" if NATO rejects Moscow's demands to lessen its military presence in Eastern Europe.
Meantime, officials in Kiev said Sunday they had proof that Moscow was involved in what they called a "massive cyberattack on government websites" in Ukraine.
The Kremlin has denied any involvement.
But Sullivan expressed US skepticism, saying, "We've been warning for weeks and months both publicly and privately that cyber attacks could be part of a broad-based Russian effort to escalate in Ukraine."
He added that the US was working with Ukraine to harden its cyber defenses, while also coordinating with US companies like Microsoft on ways to prevent future cyberattacks either in Ukraine or the US.
Sullivan added that US experts had yet to definitively confirm Russian responsibility for the cyberattack against Ukrainian targets, but added, "It would not surprise me one bit if it ends up being attributed to Russia.
"If it turns out that Russia is pummeling Ukraine with cyber-attacks and if that continues over the period ahead," he added, "we will work with our allies on the appropriate response."
