Ukrainian President Viktor Yanukovych on Friday announced an early presidential election and constitutional changes as a package of measures aimed at ending the country's political crisis. "I am initiating an early presidential election. I am also initiating a return to the 2004 Constitution with the redistribution of powers toward a parliamentary republic," Yanukovych was quoted by his press office as saying. Under that constitution, parliament had greater control over the make-up of the government, including the naming of the prime minister and the prosecutor-general. The president said he was also ready to form a new inclusive government to end the violence, which has left dozens of people dead and hundreds of others injured. Yanukovych held meetings with opposition leaders and international mediators -- the foreign ministers of Poland, France and Germany and the chairman of Russia's human rights commission -- overnight Thursday to seek ways out of the ongoing standoff. The president made concessions to the opposition in a bid to avoid further bloodshed and casualties among the demonstrators and police officers. Anti-government rallies turned violent Tuesday when the protesters attacked police with Molotov cocktails and set fire outside parliament. The police responded with stun grenades and water cannons. The clashes left at least 77 people dead and hundreds of others injured. Protests in Ukraine began last November when Yanukovych shelved a trade and economic agreement with the European Union (EU) and turned to Russia for financial aid instead. In Athens, NATO Secretary General Anders Fogh Rasmussen called for an immediate end to the violence in Ukraine and the resolution of the crisis via dialogue. "We urge all members to stop the spiral of violence ... The only way forward is through dialogue," he said after talks with Greek Prime Minister Antonis Samaras on the sidelines of an informal meeting of EU defense ministers on Friday. The Ukrainian issue overshadowed the meeting which focused on the Union's common security and defense policy. Rasmussen called on the Ukrainian government to ensure that the army would not be involved in the crisis. EU foreign ministers had agreed to adopt sanctions against Ukraine, including asset freezes, visa bans and a ban on exporting anti-riot equipment. The EU did not publish a blacklist, but Italian Foreign Minister Emma Bonino told the media that all the restrictive measures will be imposed rapidly "in the next hours." The United States also refused visas on some 20 Ukrainian government officials and individuals. Russia, which wields heavy influence on Ukraine, urged the Ukrainian government to act more resolutely amid the current unrest and demanded the radical opposition stop violence. Moscow also criticized Western threats to impose sanctions on Ukraine as blackmail and double standards. China on Friday urged the two opposing sides in Ukraine to exercise maximum restraint and seek a resolution within the legal framework.