Transcript for Russian Forces Officially Enter the Crimea Region of Ukraine
And now to what America is calling a Russian invasion of Ukraine. Russian troops in the crimean peninsula. President Obama speaking with Russian president Vladimir Putin, pulling no punches. S it unclear what the white house can do. And we have Alex Marquardt on the ground. Good morning. Reporter: Good morning, Dan. The pressure is growing. Large groups of pro-russia groups surrounding bases, ordering the forces off to they can occupy them. The international warning to end the invasion is being ignored. This morning, more unidentified pro-russia armed militias in the streets of cry me Ya's capital. They have twice asked the base command to surrender. So far they have refused. This is a Russian invasion, the U.S. Says. It has no doubt they are Russian forces and demanded their withdrawal. The Russian military must stand down. The aspirations of the people must be respected, and have political dialogue. Reporter: Putin told president Obama he has a right to protect his interests in Ukraine. We have seen it, this column of armored carriers in cry me Ya, most of the people are Russian. And they violently took over government facilities. It has fueled unrest across eastern Ukraine. In one city, pro-russian demonstrators rushed city hall and beat those who opposed them. There's a growing international chorus slamming their actions. And Canada is withdrawing their ambassador from Moscow. You want the Russian army to come here? It's all family. It's not Russian army. It's all family. They protect us. Reporter: The ukrainen military is now at the highest alert level. Just a short while ago, they announced they are pulling up reservist. And the United States in an emergency nato meeting to decide how to respond. It's unclear what the Ukrainian and U.S. Government can do. Let's talk to George stephanopoulos. Good morning. Good morning. The president said there will be costs if the Russians invade, now they have. What kind of costs can we impose? Hard to think what they can be. The United States will stop planning for the g-8 summit, supposed to be in sochi where the olympics were. That's in June. The United States could refuse to participate in that and move beyond that. Our ambassador, more of the delegation, we don't have a full-time ambassador there right now. And the big question, go farther, try to impose financial sanctions on Russia? One thing that's clear, no military action on the table. Back when Vladimir Putin went into Georgia, president bush moved warships in and sent humanitarian aid. That's about the most the united States could expect to do. And Putin just spent $50 million trying to paint a new picture for Russia. Does he care? He sees crimea as an important part of the Russian empire. It was part of it until 1954. He doesn't to want stand down. And he going to expand more broad lie into the rest of Ukraine. That could provoke more serious action from the U.S. And a decidedly lighter note, the multi-splendors light. You're going to head to the oscars today. It's always such a great night. Looking forward to being out there with robin and Lara and josh. We are talking to Ben Affleck this morning about his passion project in the Congo. But Lara sat down with Nate silver, and they have cracked the code. They have figured out what it takes to be a best picture. Nate, moving on from sports to politics to Hollywood. Thanks, George. Exactly. Following in your footsteps. Have a great time. Thank you. "This week" will be later this morning. George will crunch the Oscar Numbers and have the latest news and analysis on the crisis in Ukraine.
This transcript has been automatically generated and may not be 100% accurate.