Moscow rejected US statements about an imminent Russian invasion of Ukraine, accusing the West of misleading, while US President Joe Biden and his Russian counterpart, Vladimir Putin, spoke again on Saturday, seeking to settle the crisis diplomatically.

Amid the clouds of a possible war, the military build-up continues on the Russian and Ukrainian sides, as well as in Eastern Europe, with the North Atlantic Treaty Organization (NATO) deploying more forces.

In a statement published late Friday evening, the Russian Foreign Ministry said that the White House's statements about the situation on Ukraine were "hysterical."

The ministry added that Russia is under a media attack targeting its demands for security guarantees, in reference to the guarantees that Russia wants, especially the expansion of NATO towards its borders.

The Russian Foreign Ministry added that the West was spreading misleading news about the escalation in Ukraine to cover up what it described as its hostile steps.

The Russian statement came as US Defense Secretary Lloyd Austin assured his counterparts in Poland, Germany, Canada, France, Romania and Italy on Friday that the Russian invasion may begin at any time, and the US Department of Defense (Pentagon) said that Austin reviewed with the ministers US steps to reassure NATO allies, and stressed the unwavering commitment collective defense.

Earlier Friday, US National Security Adviser Jake Sullivan said that there is a high probability that Russia will invade Ukraine before the end of the Olympic Games in China, which concludes on the 20th of this month.

Sullivan added in a press conference at the White House that a Russian attack on Ukraine could happen any day from now, and would likely start with an air attack, and talked about the great possibilities that the Russian invasion would include major cities in Ukraine, including the capital, Kiev.

He added that Russia's forces on the borders of Ukraine and in Belarus - Ukraine's northern neighbor - appear to be in a position to launch an attack, noting that Moscow has amassed more than 100,000 soldiers of its forces on the border with Ukraine.

The US official also said that President Joe Biden would maintain contact with allies in the event that Putin took military action, and Sullivan spoke that these allies (in reference to Western countries) showed a "remarkable unity of position" against Russia.

Russia has repeatedly announced that it does not plan to invade its western neighbor, and says that it is moving its forces inside its territory to protect its security, but it has not ruled out resorting to taking an unspecified "military-technical" measure in the event that a number of security demands are not met, including a NATO promise not to annex Ukraine divorced and withdrew its forces from Eastern Europe near the Russian territory.


Diplomatic endeavors

In an effort to defuse the escalation over Ukraine, US President Joe Biden and his Russian counterpart, Vladimir Putin, are scheduled to hold a new phone conversation on Saturday.

The White House and the Kremlin confirmed the conversation, which Moscow said had taken place at an American request, while Washington said that the Russian side proposed to take place on Monday, while the American side suggested that it take place on Saturday, which was actually agreed upon.

The announcement of the new contact between the two presidents came hours after the US National Security Adviser stated that a possible Russian invasion of Ukraine was imminent.

In conjunction with the scheduled conversation between the US and Russian presidents, the Russian and French presidents will hold a similar contact, according to a Kremlin spokesman.

In this context, the US Department of Defense announced on Friday that the US and Russian Chiefs of Staff spoke by phone.

For his part, US Secretary of State Anthony Blinken, in a phone call with his Ukrainian counterpart Dmitry Kuleba, on Friday, affirmed Washington's support for Kiev against any possible Russian aggression.

On Friday, US President Joe Biden held an emergency remote summit with leaders of European countries in addition to Canada, NATO, Poland and Romania.

The White House said that the leaders participating in the summit expressed their concern about Russia's continued massing of its forces on the border with Ukraine, stressing their desire to reach a political solution to the crisis.

Before that, the US president met with his national security advisers to discuss the Russian military build-up on the border with Ukraine.

Diplomatically also, Russian Defense Minister Sergei Shoigu called - during his meeting in Moscow with his British counterpart Ben Wallace - the West to stop sending weapons to Ukraine.

Wallace said he had received assurances from Russia that it did not intend to invade Ukraine, and warned that any Russian military action would have dire consequences.


The timing of the sweep and withdrawal of nationals

And the US news agency Bloomberg quoted US officials, whom it described as insiders, that Russia's move to invade Ukraine may start next Tuesday.

According to these officials, Russia's actions could include a provocation in the Donbass region, where the Ukrainian army has been fighting for years against Moscow-backed separatists, or an attack on the country's capital, Kiev.

These officials also emphasized that they did not believe that Putin had made a final decision on Ukraine.

As the atmosphere of war formed, the United States, Britain, Norway, the European Union, Japan and Israel called on their nationals and non-essential personnel to leave Ukraine.

The State Department said that the invitation to the American nationals to leave Ukraine includes employees of the Organization for Security and Cooperation in Europe mission.


NATO defenses

Regarding the military buildup, the Pentagon said that the additional US forces, numbering up to 5,000, would contribute to deterring any possible aggression against the eastern flank of NATO.

And the US Department of Defense revealed that the additional forces from the 82nd Airborne Division will arrive in Poland early next week.

She explained that Defense Secretary Lloyd Austin had ordered the dispatch of 3,000 US troops to Poland over the next two days.

In the same context, the European Command of the American forces announced that American F-16 fighters will arrive in Romania from its air base in Germany.

The European Command said in a statement that the American planes will join Italian fighters in Romania to enhance regional security in the Black Sea region in light of the existing tensions due to the Russian military build-up near Ukraine.

The Deputy Commander of the NATO Air Command stated that the "F-16" fighters will significantly enhance the deterrence position of the Alliance in the southeastern region.

The White House had stated that the United States and its allies had agreed to strengthen NATO's defense in Eastern Europe, and to coordinate efforts to deter what it described as Russian aggression, including imposing harsh sanctions on Moscow.


Military exercises

In contrast to the ground and air maneuvers conducted by the Russian forces inside Russia and also in neighboring Belarus, in addition to the movement of warships in the Black Sea, Ukrainian Defense Minister Oleksiy Reznikov announced the start of military exercises throughout the country.

He added that the maneuvers will be held in areas corresponding to the maneuvers that Russia is conducting on its borders, especially those that started Thursday on the territory of Belarus.

In the same context, the Ukrainian Air Force conducted military exercises at Air Base 203 near the northeastern city of Kharkiv.

These maneuvers include special forces training on airdrop operations, in which Turkish Bayraktar drones, American Javelin anti-tank and armor missiles, and British “N-Low” anti-armor missiles are also used. The maneuvers will also test the capabilities of the ground forces, including armored vehicles, artillery and missile launchers Rapid deployment to repel any possible Russian attack.

In turn, the correspondent of the American news website BuzzFeed published a number of satellite images taken during the past 24 hours, which he said show the continuous Russian military reinforcements in the Crimea and Belarus.

He added - in a tweet - that these images reveal the new and wide spread operations throughout the region.

Earlier, Russia and Ukraine said they had failed to achieve any breakthrough, a day after talks in Berlin between the parties to the "Normandy formula" to stop the fighting between Ukraine and armed separatists in the east of the country loyal to Moscow.

These parties include Russia and Ukraine, as well as France and Germany.