U.S. pledges to put Russia on defensive at UN Security Council

The U.S. worked Sunday to ramp up diplomatic and financial pressure on Russia over Ukraine, promising to put Moscow on the defensive at the UN Security Council as lawmakers on Capitol Hill said they were nearing agreement on 'the mother of all sanctions.'

The American ambassador to the United Nations said the Security Council will press Russia hard in a Monday session to discuss its massing of troops near Ukraine and fears it is planning an invasion.

"Our voices are unified in calling for the Russians to explain themselves," Ambassador Linda Thomas-Greenfield said of the U.S. and the other council members on ABC's "This Week." "We're going into the room prepared to listen to them, but we're not going to be distracted by their propaganda."

Ukraine's ambassador to the U.S., Oksana Markarova, warned that Russian President Vladimir Putin is bent on waging an "attack on democracy," not just on a single country. It's a case that some senior foreign policy figures have urged President Joe Biden to make, including at the Security Council.

"If Ukraine will be further attacked by Russia, of course they will not stop in Ukraine," Markarova said on CBS's "Face the Nation."