Ukraine-Russia crisis: What to know as tensions hit new high


              In this handout photo provided by the Ukrainian Presidential Press Office, Ukrainian President Volodymyr Zelenskyy speaks to citizens in Mariupol, Donetsk region, eastern Ukraine, Thursday, Feb. 17, 2022. U.S. Secretary of State Antony Blinken told ABC News that Russian President Vladimir Putin "can pull the trigger. He can pull it today. He can pull it tomorrow. He can pull it next week. The forces are there if he wants to renew aggression against Ukraine." NATO Secretary-General Jens Stoltenberg and Ukrainian President Volodymyr Zelenskyy also dismissed the Russian claims. (Ukrainian Presidential Press Office via AP)
            
              This Feb. 16, 2022 satellite image provided by Maxar Technologies shows a military convoy headed westbound at Rechitsa in Belarus. (Satellite image ©2022 Maxar Technologies via AP)
            
              This Feb. 15, 2022 satellite image provided by Maxar Technologies shows an overview of road construction and new pontoon bridge over the Pripyat River, Belarus. (Satellite image ©2022 Maxar Technologies via AP)
            NATO Secretary General Jens Stoltenberg speaks during a media conference after a meeting of NATO defense ministers at NATO headquarters in Brussels, Thursday, Feb. 17, 2022. U.S. Defense Secretary Lloyd Austin and his NATO counterparts held talks on Thursday with ministers from Ukraine and Georgia, as Russia's military buildup around Ukraine fuels one of Europe's biggest security crises in decades. (AP Photo/Olivier Matthys) In this handout photo provided by the Ukrainian Presidential Press Office, Ukrainian President Volodymyr Zelenskyy greets Ukrainian coast guards in Mariupol, Donetsk region, eastern Ukraine, Thursday, Feb. 17, 2022. U.S. Secretary of State Antony Blinken told ABC News that Russian President Vladimir Putin "can pull the trigger. He can pull it today. He can pull it tomorrow. He can pull it next week. The forces are there if he wants to renew aggression against Ukraine." NATO Secretary-General Jens Stoltenberg and Ukrainian President Volodymyr Zelenskyy also dismissed the Russian claims. (Ukrainian Presidential Press Office via AP) 
              A Ukrainian serviceman stands in a trench at a frontline position outside Popasna, the Luhansk region, in eastern Ukraine, Wednesday, Feb. 16, 2022. Ukrainians defied pressure from Moscow with a national show of flag-waving unity Wednesday, while the West warned that it saw no sign of a promised pullback of Russian troops from Ukraine's borders despite Kremlin declarations of a withdrawal. (AP Photo/Vadim Ghirda)