WASHINGTON – President Joe BidenRussian President Vladimir PutinWe spoke on Thursday by phone as tensions rise due to a large-scale military buildup near the Ukrainian border.

At 3:35 PM ET, the call started. ET, and the call lasted for 50 minutes according to White House.

You can reach us by calling second known discussion between the two leaders this monthPutin asked for it. According to the Russian president, despite the massive presence of thousands of troops at Ukraine’s borders, Moscow has not been preparing for an invasion of its ex Soviet neighbor.

Putin made conditions for nonnaggression. He promised that Russian troops would not attack Ukraine if Kyiv refuses to accept NATO membership. Russia described NATO’s expansion to the east as “a red line”, which poses security risks for Moscow.

Ukraine sought admission to the strongest military alliance in the world since 2002. where the group’s Article 5 clauseAn attack on one country in the group is considered to be an attack against all.

Biden refused to take Putin’s red line during a call earlier in the month and warned instead that Washington and its European allies would be prepared to place economic and other countermeasures should Ukraine breach its sovereign borders.

A senior Biden administration official said that while we were prepared for diplomatic diplomacy, and for a path forward in diplomacy, “we are also ready to respond to Russia’s further invasion of Ukraine.” He spoke under anonymity to give details before the conference call.

The official spoke of Moscow’s invasion in Crimea 2014 and said that they had coordinated with their allies in imposing severe sanctions against the Russian economy.

The Ukraine warned America and European allies for months that Russian troops are encroaching on its eastern border. It has brought back memories of Russia’s 2014 annexation and massing of troops along its eastern border. This evoked a lot of international outrage that led to a number of sanctions being imposed on Moscow.

Simon Miles is an assistant professor at Duke University’s Sanford School of Public Policy. He described the discussions between Putin and Biden as fruitful, but said that there would have to be a solution with the Ukrainian government.

“Today’s phone call between presidents Biden and Putin comes at a critical point in European security. Russian troops are on Ukraine’s border in significant numbers, and in a configuration which has analysts rightly worried about offensive military action,” wrote Miles, an expert on Russia and the former Soviet Union.

“But one thing is clear: This is a crisis of the Kremlin’s making,” Miles said, adding, “What Putin’s endgame is remains unclear.”

CNBC reported earlier this month that Ukraine’s foreign ministry stated to CNBC, “Russia is in a position quickly to invade” if Putin wanted to do so.

“Putin is still undecided about whether to conduct a military operation.” Dmytro Kuleba told CNBC. But if he chooses to act, everything will be done in a flash.