US national security advisor Jake Sullivan said that the United States believes Russia could launch an invasion of Ukraine this week, but is still holding out hope diplomacy can prevail.

On CNN’s “State of the Union” program, he added that “if there is a military invasion of Ukraine by Russia, it’s likely to begin with a significant barrage of missiles and bomb attacks.”

The Biden administration and its allies are developing new possible sanctions against Russia if the situation escalates, he stressed.

Sullivan claims that the US and its allies are increasingly revealing their intelligence findings to stop the war.

“A war on Ukraine can be averted”

Pentagon press secretary John Kirby said on Sunday that time is "shrinking" when it comes to finding a diplomatic resolution to the Russian military buildup at the Ukrainian border.

In an interview on Fox News, he added, "But again, we've said it and we still believe it today that there is still a time and a space for a diplomatic path forward," stressing that "we still believe that there's a way to de-escalate the tensions here find a peaceful way out of this so that a war in Ukraine can be averted."

Biden and Zelensky to speak Sunday

President Joe Biden and Ukrainian President Volodymyr Zelensky are expected to speak on Sunday, the Ukrainian Presidency said.

These developments came after Russian President Vladimir Putin and US President Joe Biden held a telephone call on Saturday.

The phone conversation, which lasted more than an hour, saw Biden talking about how the invasion would “produce widespread human suffering and diminish Russia’s standing,” and cause “irrevocable reputational damage” for the country.

On the other hand, Putin stressed that the West is not pressuring Ukraine enough to implement the Minsk agreements, which are instrumental to balancing the situation.

A senior foreign policy adviser in the Kremlin, Yury Ushakov, described the conversation between the two presidents as “balanced and businesslike” and noted that both have agreed to “continue contacts at all levels.” Nevertheless, the Kremlin adviser rejected claims emanating from the US that a Russian attack was imminent: “Hysteria has reached its peak.”

This alarmist rhetoric has been prevailing recently in all US official and media reports, despite Moscow continuously reassuring that it has no intention of invading Ukraine.

Russia’s discontent with Washington’s approach was even interestingly echoed by Ukrainian President Volodymyr Zelenskiy, who criticized the White House’s tone of messaging that is creating panic in the country without offering founded proof about the possible “invasion”.