cnn reporters are covering it all. >> reporter: i'm delia gallagher in rome. pope francis has received an invitation from the mayor of kyiv to come to the city. the mayor wrote to the pope saying his presence would, quote, be key for saving lives and paving a path to peace. the vatican acknowledged the pope did receive the letter. they did not say whether he would be taking up his offer on the mayor but the pope was close to the people suffering in the city, to the city's administration, and to all those who have had to flee. >> reporter: secretary of defense lloyd austin arrived here a short time ago where he will be meeting with counterparts all day to discuss the situation on the ground in ukraine. they will begin with a military assessment of ukraine's military operations and discuss the reinforcements to those feeling very vulnerable in this russian aggression. it all comes ahead of president biden's trip to nato where he