CBS news special report I'm Howard -- -- -- President Obama is about to enter the White House briefing room with a statement about Ukraine's. As Moscow appears ready to possibly annex breakaway Crimea. This follows a referendum yesterday that the US and its European allies have labeled as illegitimate and illegal. With us live correspondent Peter -- at the White House where new sanctions were announced this morning Peter what Morton in the White House do to stop Russia from annexing Crimea. Well first of all Howard a senior official described today's move is the toughest set of sanctions on Russia's since the end of the Cold War bit. To answer your question veterans of the US Russian dealings over the years say there are very few good options. In fact a senior official told us just this morning that Russian President Putin is expected to announce plans to. -- Crimea as early as tomorrow now on the sanctions. On the listed eleven people including two senior prudent aids. A move but designed to hit home according to one US official. Other Russian officials in those described as cronies are also on the list Ukraine's fugitive president -- -- which also here's President Obama. The war in Iraq. In recent months. The citizens of Ukraine have made their voices heard. We have been guided by a fundamental -- The future of Ukraine. Must be decided by the people of Ukraine. That means Ukraine's sovereignty and territorial integrity must be respected. And international law must be upheld. And so Russia's decision to send troops into Crimea as brightly drawn global condemnation. From the start the United States is mobilizing international community in support of -- To isolate Russia for its actions and reassure our allies and partners. We saw this -- national unity again over the weekend when Russia stood alone in the UN Security Council defending its actions in Crimea. And as I told present -- yesterday. The referendum in Crimea was a clear violation of Ukrainian. Constitutions. And international law and will not be recognized by the international community. Today I'm announcing a series of measures that will continue to increase the cost on Russia and on those responsible for what is happening in Ukraine. First. As authorized by the executive order I signed two weeks ago. We are imposing sanctions on specific individuals responsible for undermining the sovereignty. Territorial integrity and government of Ukraine. We're making it clear that there are consequences for their actions. -- I have signed a new executive order that expands the scope of our sanctions. As an initial step I'm authorizing sanctions on Russian officials entities operating in the arms sector in Russia and individuals. Who provide material support to senior officials of the Russian government. And if Russia continues to interfere in Ukraine we stand ready to impose further sanctions. Third. We're continuing our close consultations with our European partners who today in Brussels move ahead with their own sanctions against -- Tonight Vice President Biden departs for Europe where you will meet with leaders of our NATO allies Poland Estonia Latvia and Lithuania. And I'll be traveling to Europe next week. Our message will be clear. As NATO allies we have a solemn commitment to our collective defense and we will uphold this commitment. Fourth will continue to make clear to Russia that further provocations will achieve nothing except to further isolate Russia diminish its place in the world. The international community will continue to stand. Together to oppose any violations of greater sovereignty and territorial integrity. And continued Russian military intervention in Ukraine will only deepen Russia's diplomatic isolation. And exact a greater hole on the Russian economy. Point four we can calibrate our response based on whether Russia chooses to escalate or to the escalate the situation. Now I believe there's still a path to resolve this situation diplomatically. In -- way that addresses the interests of both Russia and Ukraine. That includes Russia pulling its forces. In Crimea back to their -- supporting the deployment of additional international monitors in Ukraine. And engaging in dialogue with the Ukrainian government. Which is indicated its openness to pursuing constitutional reform as they move forward towards elections this spring. But throughout this process we're gonna stand firm in our unwavering support. For Ukraine. As I told prime minister -- and your last week the United States stands with the people of Ukraine and the right to determine their own destiny. We're gonna keep working with congress and our international partners to offer Ukraine's economic support. That it needs to weather this crisis and to improve the daily lives of the Ukrainian people. And as we go forward we will continue to look at the range of ways we can help or Ukrainian friends achieve their universal rights and the security. Prosperity. And dignity. That they -- Thanks very much. Will be available for what thank. I just. President Obama leaving the White House briefing room taking no questions about Ukraine. He's listed new sanctions punishing Russian officials who were supporting the military effort in Crimea. He repeated yesterday's referendum will not be recognized by the international community he said though there still a path to resolve the situation diplomatically. Peter -- live at the White House is the US. Is there any real hope of turning this around. I don't think so immediately Howard it again a number of the experts. On these types of peace talks with the Russians and again we have to say this is a new chapter. In these types of very very get tough dealings that -- experts tell us. Probably not in fact just before the president came out. A senior official. Acknowledged that the President Putin of Russia is expected as early as tomorrow. To announce the official annexation by Russia of Crimea. That statement even as administration officials said that the -- vote that was a stage yesterday that Russian promoted vote yesterday. Was illegitimate and that the US of course will not recognize that the outcome of that vote. But it does sound like the US is in sync with the European Union business. Well that's right the European Union will announce its own sanctions and its own targets for sanctions. Later today or more likely tomorrow we're told -- some of the names on that list will be the same as as those on the a list that the US release today. And again it's noteworthy that there are two top -- aids. Who face sanctions and by sanctions but we mean Howard. That the US is freezing the assets and US held assets of these people. A trying to block them from any transactions in dollars. Or. Also. Taking action to prevent any Americans from doing business with the people on that list also on the list is the fugitive president of Ukraine the guy who left you have a few weeks ago victory got to cope which he too targeted. With US sanctions. It's correspondent Peter -- at the White House this is gonna CBS news special report. I'm Howard -- -- Washington.