PUTIN AND BIDEN HAVE STARTED A STRONG PHONE CHAT ABOUT THE UKRAINE CONFLICT.

With the threat of war growing, Russian President Vladimir Putin and US President Joe Biden held a high-stakes phone chat on Saturday, as a tense world watched and feared that an invasion of Ukraine could start in days.

Prior to speaking with Biden, Putin spoke on the phone with French President Emmanuel Macron, who met with him in Moscow earlier this week to try to address the world's largest security issue since the Cold War. According to a Kremlin readout of the call, no progress was achieved toward lowering tensions.

The United States declared plans to evacuate its embassy in Kiev, and Britain joined other European nations in pushing its people to leave Ukraine, indicating that American officials were preparing for the worst-case scenario.

Russia has amassed around 100,000 troops near the Ukraine border and has moved troops to neighbouring Belarus for drills, but it denies that it plans to attack Ukraine.

The timing of any potential Russian military action remained a major concern.

According to a US official familiar with the results, the US received evidence that Russia is targeting Wednesday as a target date. The official, who was not authorised to speak to the press and spoke on the condition of anonymity, would not specify how conclusive the intelligence was. The White House made it clear that the US does not know for sure whether Putin is planning an invasion.

However, US officials have stated again that Russia's military buildup near Ukraine has reached the point where it may invade at any time.

"Provocative predictions about an allegedly planned Russian 'invasion' of Ukraine," according to a Kremlin statement regarding the Putin-Macron call. Russia has long denied that it intends to attack its neighbour militarily.

Putin also complained in the call that the US and NATO had failed to meet Russian demands that Ukraine be barred from joining the military alliance and NATO forces be pulled back from Eastern Europe.

The call between Biden and Putin began at 11:04 a.m. EST, according to the White House. The call was made from Camp David by Biden.

Although Biden has stated that the US military will not enter a war in Ukraine, he has guaranteed that the US will impose severe economic sanctions on Moscow in coordination with international allies.

"Further Russian aggression would be faced with a resolute, enormous, and coordinated trans-Atlantic response," US Secretary of State Anthony Blinken told his Russian counterpart on Saturday.

Meanwhile, as he watched military drills near Crimea, which Russia took from Ukraine in 2014, Ukrainian President Volodymyr Zelenskyy tried to project calm.

"We are not terrified, we are not panicked, and everything is under control," he stated.

On Saturday, US Defense Secretary Lloyd Austin and his Russian colleague, Sergei Shoigu, spoke on the phone.

The British troops who were training the Ukrainian army were also planning to leave the country. Germany, the Netherlands, and Italy have all requested that their citizens go as quickly as possible.

According to a State Department travel alert issued on Saturday, most American embassy workers in Kyiv have been instructed to leave, and other US individuals should leave the country as well.

The Defense Ministry summoned the US embassy's military attache on Saturday after the navy detected an American submarine in Russian waters near the Kuril Islands in the Pacific, escalating tensions between the two countries. The submarine refused to leave, but did so when the navy utilised "necessary means," according to the ministry.

The Pentagon added to the impression of danger by sending an additional 3,000 US troops to Poland to reassure allies.

Jake Sullivan, Biden's national security adviser, said Americans in Ukraine should not expect the US military to rescue them if air and rail connectivity is disrupted as a result of a Russian invasion.

Several NATO countries, including the United Kingdom, Canada, Norway, and Denmark, as well as non-NATO partner New Zealand, have ordered their citizens to leave Ukraine.

Russian military intervention, according to Sullivan, might begin with missile and air attacks, followed by a land offensive.

"Russia has all the forces it needs to launch a significant military operation," Sullivan said, adding that "Russia might chose to launch a massive military operation against Ukraine in very short order." According to him, the scope of an invasion might range from a small infiltration to a strike on Kyiv, Ukraine's capital.

The United States' claim of urgency was mocked by Russia. "The White House's panic is more suggestive than ever," a Russian Foreign Ministry spokesperson, Maria Zakharova, said. "The Anglo-Saxons are in desperate need of a conflict. At any price. Provocations, lies, and threats are popular ways for them to solve their own issues."

In response to fears about probable military action from the Ukrainian side, Zakharova said her country had "optimised" staffing at its own embassy in Kyiv.

In addition to the more than 100,000 foot troops positioned around Ukraine's eastern and southern borders, the Russians have deployed missile, air, naval, and special operations units, as well as supplies to maintain a conflict, according to US sources. Russia deployed six amphibious assault ships into the Black Sea this week, bolstering its ability to land commandos on the shore.

Sullivan's harsh threat has hastened the predicted time period for an invasion, which many observers had thought would not happen until after China's Winter Olympics on Feb. 20. According to Sullivan, the administration has warned that conflict might break out at any time due to a combination of a new Russian force deployment on Ukraine's borders and unnamed intelligence indicators.

"We can't name the day or the hour at this point," Sullivan added, "but it is a very, very distinct possibility."

As reassurance to allies on NATO's eastern flank, Biden has increased the US military posture in Europe. On top of the 1,700 soldiers already on their way to Poland, an extra 3,000 soldiers have been ordered. The US Army is also relocating 1,000 troops from Germany to Romania, which shares a border with Ukraine with Poland.

Russia is requesting that the West exclude former Soviet republics from NATO membership. It also wants NATO to stop stationing weapons near its border and withdraw alliance forces from Eastern Europe, demands that the West has firmly rejected.

Since 2014, when Ukraine's Kremlin-friendly president was forced from office by a popular uprising, Russia and Ukraine have been at odds. Moscow retaliated by annexing the Crimean Peninsula and then supporting a separatist insurgency in eastern Ukraine, where over 14,000 people have been murdered in conflict.

Large-scale warfare were halted by a 2015 peace pact brokered by France and Germany, but frequent skirmishes have continued, and efforts to establish a political settlement have faltered.