US Vice President Joseph Biden on Monday called Ukrainian President Viktor Yanukovych to voice " deep concern" about the "growing potential for violence" in Ukraine, urging his government to de-escalate the situation. The phone talks came as hundreds of thousands of demonstrators took to the streets in Kiev, Ukraine's national capital, over the weekend, demanding Yanukovych's resignation and tearing down the city's main statue of Vladimir Lenin in protest. The growing protests, the largest since 2004, were triggered off by Yanukovych's announcement on Nov. 21 of the decision to suspend signing political and trade agreements with the European Union (EU), a path to eventual EU membership, reportedly under pressure from Russia. Biden "underscored the need to immediately de-escalate the situation and begin a dialogue with opposition leaders on developing a consensus way forward for Ukraine," the White House said in a readout of the phone conversation. "The vice president reaffirmed the strong support of the United States for Ukraine's European aspirations and welcomed President Yanukovych's commitment to maintaining this path," the White House said. Catherine Ashton, the EU's foreign policy chief, and Victoria Nuland, the U.S. assistant secretary of state for European and Eurasian affairs, will travel to Kiev on Tuesday. Biden also made a call to Yanukovych last month to express his disappointment at Kiev's suspension of the preparations for signing the agreements with the EU.