Putin made a promise to protect a bank that is partially owned by a former ally who has been blacklisted by Washington. Russia's response to the financial and visa restrictions imposed by the US included producing its own blacklist. Despite his allies laughing off the sanctions, the Moscow stock exchange saw a significant drop in shares due to threats from President Obama about targeting major sectors of the economy if Russia expanded its presence beyond Crimea. In response to claims by Russia that troop movements on the Ukraine border were simply military exercises, Washington remained doubtful and the OSCE agreed to send monitors to Ukraine. The financial pressure continued to increase with Visa and MasterCard ceasing payment processing for a Russian bank owned by individuals on the US blacklist. European Union leaders also imposed sanctions on several Russian officials and expressed their desire to reduce reliance on Russian energy. Following the annexation of Crimea, Putin signed legislation ratifying the treaty making Crimea part of Russia and creating two new administrative districts. Celebrations and fireworks were held in Crimea, with many ethnic Russians expressing a desire for improved conditions and investment from Russia, while Ukrainian and Tatar residents remained cautious and wary of the annexation. A referendum held last Sunday in Crimea, following the seizure of the region by Russian troops, overwhelmingly supported union with Russia. However, this referendum was criticized by the United States and the European Union as being illegitimate. This paved the way for Crimea's annexation by Russia within a week. President Obama's decision to target the financial assets of those close to Putin, including Bank Rossiya, has escalated tensions diplomatically. Putin denied any involvement of Bank Rossiya in the events in Crimea, stating that it primarily serves clients in Russia's energy sector. Putin, who believes Crimea has the right to self-determination, announced that he will transfer his wages to Bank Rossiya. Other individuals targeted by the U.S. blacklist include oil trader Gennady Timchenko and the Rotenberg brothers, who are connected to major contracts in gas pipelines and the Sochi Olympics. The European Union leaders also decided to expedite their efforts for secure energy supplies during discussions on Friday. Despite progress in diversifying energy sources since previous crises, Russia still provides a significant portion of the EU's oil and gas, with a large amount passing through Ukraine. European Council President Herman Van Rompuy stated that member states will support each other to maintain energy supplies in case of any disruption from Moscow. EU countries, which currently negotiate with Russia individually for gas supplies, will aim to collectively negotiate deals with Moscow to strengthen their bargaining position. Van Rompuy stated the need for an energy union. Angela Merkel suggested US shale gas could be an option for European countries. Obama is set to discuss the issue with EU leaders. US credit card companies Visa and MasterCard stopped services for Russia's SMP bank, causing concern for foreign banks and companies. French banker in Moscow criticized the sanctions, warning of potential ripple effects on the Russian economy. Obama mentioned considering sanctions on various economic sectors if Russia intervenes in Ukraine. Ukrainian troops in Crimea are unable to stop Russia's control of the region. German Foreign Minister Frank-Walter Steinmeier expressed concern about the ongoing instability and threat in Ukraine, urging OSCE observers to begin their work promptly. European governments, including Germany and France, took actions against Russia by suspending defense-related exports and military cooperation. In Brussels, EU leaders signed a political agreement with Ukraine's new leadership and pledged financial aid once a deal is reached with the IMF. Protests in Ukraine began after former President Yanukovich refused to sign an association agreement with the EU. Russia's stock index dropped following the announcement of sanctions by Obama. Credit ratings agencies Fitch and S&P changed their outlooks on Russia to negative due to the potential impact of sanctions. Prime Minister Dmitry Medvedev stated that Russia would increase financial pressure on Ukraine, demanding repayment of $11 billion under a gas supply contract.