A senior administration official said Mr. Biden and Putin and agreed to a \u00ab\u00a0sequence of strategic stability dialogue.\u00a0\u00bb<\/b>
\nin a phone call on Thursday that the U.S. and its allies will react \u00ab\u00a0decisively\u00a0\u00bb if Ukraine is invaded, White House press secretary Jen Psaki said. A senior administration official said Mr. Biden and Putin and agreed to a \u00ab\u00a0sequence of strategic stability dialogue.\u00a0\u00bb The call comes as along the border with Ukraine, and U.S. intelligence has warned Russia could invade Ukraine as soon as January. Meanwhile, a U.S. official confirmed to CBS News that an American spy plane flew a mission over Ukraine on Thursday. The flight was by a JSTARS aircraft, which is a radar plane specifically designed to track ground movements. The senior administration official said Mr. Biden laid out two paths, one focused on democracy and the other focused on deterrence and \u00ab\u00a0significant costs and consequences should Russia choose to proceed with further invasion of Ukraine.\u00a0\u00bb The senior administration official said the tone of Mr. Biden’s call with Putin was \u00ab\u00a0serious and substantive\u00a0\u00bb and its primary purpose was to set the \u00ab\u00a0tone and tenor of diplomatic engagement\u00a0\u00bb scheduled for next month. The upcoming talks will help \u00ab\u00a0determine more precisely the contours\u00a0\u00bb of the areas where there can be agreement between the two leaders, the official said. Mr. Biden urged Putin to deescalate tensions with Ukraine, and the official said the U.S.’ focus is \u00ab\u00a0really on actions and on indicators not on words\u00a0\u00bb and will continue to prepare for whatever decision Putin makes with regard to Ukraine. The U.S. will continue a \u00ab\u00a0very intensive period of consultation\u00a0\u00bb with allies over the next week before the NATO-Russia council talks, the senior administration official said. \u00ab\u00a0There will be a very careful and very intensive coordination transparency among our partners and allies,\u00a0\u00bb the official said. Russia has built up an estimated 100,000 troops near the Ukrainian border. Despite recent reports that the Russians have withdrawn 10,000 troops from the area, the senior administration official said the White House is \u00ab\u00a0greatly concerned\u00a0\u00bb about the still \u00ab\u00a0significant Russian troop presence\u00a0\u00bb along the border. CBS News has reported that the 10,000 withdrawn troops is just a fraction of the number that still remains at the border. David Martin, Fin Gomez and Fritz Farrow contributed to this report.<\/p>\n