Putin has pledged to protect a bank that is partially owned by a former ally who has been blacklisted by Washington. Russia's response to the latest financial and visa restrictions will be similar after they created their own blacklist. Despite his allies downplaying the US sanctions, the Moscow stock exchange experienced a significant drop in share value due to President Obama's threat to target key sectors of the economy if Russia expands its control beyond the Black Sea peninsula. The situation further escalated with Visa and MasterCard halting payments for a Russian bank owned by individuals on the US blacklist. European leaders, along with Obama, continue to assert that Crimea remains part of Ukraine and have imposed sanctions on several Russian officials. In response to the crisis, the EU is determined to reduce its dependence on Russian energy and has signed a political agreement with the current leadership in Kiev. Putin has signed a law ratifying Crimea's annexation into Russia and has established two new administrative districts. The annexation was met with celebrations in Crimea, particularly among ethnic Russians, while Ukrainian and Tatar residents remained apprehensive. A recent referendum in Crimea, where Russian troops had taken control, overwhelmingly supported the region's union with Russia. However, this move was criticized by the US and EU as being illegitimate. This led to Obama imposing financial sanctions on individuals who have been associated with Putin since his time as mayor of St Petersburg. Putin denied any connection between Bank Rossiya, a St Petersburg-based bank, and the events in Crimea. He also pledged to transfer his wages to this bank. Other individuals on the US blacklist include oil trader Gennady Timchenko and the Rotenberg brothers. European leaders also discussed increasing their energy security at a recent meeting, as Russia currently supplies a significant portion of the EU's oil and gas. Herman Van Rompuy, European Council President, stated that member states would support each other in case of any disruption in energy supplies from Russia. EU countries are also considering negotiating supply deals with Moscow collectively to enhance their bargaining power. Van Rompuy stated the importance of moving towards an energy union. Merkel suggested that US shale gas could be an option for European countries looking to diversify. Obama is set to discuss this issue with EU leaders next Wednesday. US credit card companies Visa and MasterCard stopped providing services for payment transactions with Russia's SMP bank, causing concern for foreign banks and companies. Obama is considering further sanctions against Russia, including in economic sectors such as financial services, oil and gas, metals and mining, and the defence industry if military actions continue in Ukraine. Ukrainian troops in Crimea have been unable to stop Russia's takeover of the peninsula. German Foreign Minister Frank-Walter Steinmeier expressed concern over the unstable and threatening situation in Ukraine, urging OSCE observers to begin their work promptly. European governments, including Germany and France, took various actions against Russia, such as suspending defence-related exports and military cooperation. The EU leaders in Brussels showed their support for Ukraine's new leadership by signing a political agreement with Prime Minister Arseniy Yatseniuk and promising financial aid once Kiev reaches a deal with the IMF. The IMF is expected to report on talks with Ukraine regarding a loan programme linked to economic reforms. The protests in Ukraine were sparked by former President Yanukovich's refusal to sign an association agreement with the EU. Russia's stock index fell due to concerns about sanctions, while credit ratings agencies downgraded their outlooks on Russia. Prime Minister Dmitry Medvedev announced that Russia would increase financial pressure on Ukraine to repay $11 billion under a gas supply contract.