The United States told the UN Security Council on Tuesday that Venezuela’s President Nicolas Maduro was stepping up a crackdown on the opposition-controlled National Assembly and called on countries to respond with concrete actions.The council met behind closed doors at the request of European countries to hear a briefing on the political and humanitarian crises in Venezuela and details of an EU-backed diplomatic push to end the stalemate. US Acting Ambassador Jonathan Cohen raised alarm over the arrest on May 8 of Edgar Zambrano, a senior opposition leader and first vice president of the National Assembly.“We are concerned Zambrano’s arrest is a major escalation of the ongoing crackdown by the Maduro regime against the National Assembly,” said a statement from the US mission to the United States. “The United States calls on all member states to be prepared to take concrete actions in response to the Maduro regime’s repression throughout Venezuela,” it added.The United States is among more than 50 countries backing opposition leader Juan Guaido, who declared himself interim president on January 23 but has since failed to force Maduro to step down. Guaido blames Maduro for Venezuela’s economic problems, which have forced millions of Venezuelans to flee the country in search of livelihoods abroad.The council heard a report from French Deputy UN Ambassador Anne Gueguen on a plan by the EU-backed International Contact Group to end the standoff in Venezuela. The contact group, made up of about a dozen European and Latin American countries, plans to send envoys to Caracas soon to discuss holding elections.The group “has the capacity to push the parties to engage in a political process that would lead to free, credible and transparent elections,” Gueguen told AFP. The United Nations is stepping up plans to address the humanitarian crisis in Venezuela, where 7 million people — 25 percent of the population — are in need of food, medicine and other basic supplies.The UN resident coordinator met Monday with Maduro and other government officials in Caracas to discuss a proposed UN humanitarian response plan, UN officials said.The United Nations plans to appoint a humanitarian coordinator soon to oversee a rollout of aid to Venezuela.a Maduro has repeatedly maintained that there is no humanitarian crisis in his country and that US sanctions are to blame for the hardships of Venezuelans.