(Reuters) - Here's what you need to know about the Ukraine crisis right now:

       HEADLINES

       * Russia launched an all-out invasion of Ukraine by land, air and sea on Thursday, the biggest attack by one state against another in Europe since World War Two and confirmation of the West's worst fears.

       * Russian President Vladimir Putin says his aim is to demilitarise and 'denazify' Ukraine.

       * Russian troops attacked Ukraine from Belarus as well as Russia and from annexed Crimea, Ukraine's border guard service said. Missiles rained down on Ukrainian cities and explosions were heard near the capital Kyiv.

       * Ukrainian President Volodymyr Zelensky appealed to world leaders to impose all possible sanctions, saying Putin wanted to destroy the Ukrainian state.

       * The European Union will impose new sanctions, freezing Russian assets, halting access of its banks to the European financial market and targeting "Kremlin interests" over its "barbaric attack", senior officials said.

       * U.S. President Joe Biden said Washington and its allies would impose "severe sanctions".

       * Central European countries started preparations to receive potentially hundreds of thousands of people fleeing Ukraine.

       * Moldova declared a state of emergency as dozens of cars queued on its border with Ukraine, according to Moldovan media websites.

       * Russia suspended movement of commercial vessels in the Azov sea, but kept its Black Sea ports open for navigation, its officials and five grain industry sources said.

       * Ukraine asked Turkey to close the Bosphorus and Dardanelles straits to Russian ships, Ukraine's ambassador to Ankara said.

       QUOTES

       - "I have decided to conduct a special military operation... to protect people who have been subjected to bullying and genocide," Putin said. "And for this we will strive for the demilitarisation and denazification of Ukraine.

       "And to bring to court those who committed numerous bloody crimes against civilians, including against citizens of the Russian Federation."

       - "Putin has just launched a full-scale invasion of Ukraine. Peaceful Ukrainian cities are under strikes," Ukrainian Foreign Minister Dmytro Kuleba said on Twitter.

       COMING EVENTS

       * Biden will meet with his G7 counterparts Thursday to map out more severe measures against Russia after Putin launched what Biden called "a premeditated war" against Ukraine.

       * European Union leaders will discuss further sanctions at an emergency meeting on Thursday, the EU said.

       * NATO ambassadors will hold an emergency meeting on Thursday.

       * The U.N. Security Council will discuss a resolution condemning the invasion.

       (Editing by Jon Boyle and John Stonestreet)