Rome (dpa) - The heads of Russian and US diplomacy are to take part in an international meeting on the Libyan crisis due to be held in Rome on December 13, Italian Foreign Minister Paolo Gentiloni said Friday.US Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov "will certainly be present," along with representatives of other members of the UN Security Council, European and Middle Eastern nations, Gentiloni said.The aim is to renew pressure on warring Libyan sides to agree to a national unity government deal brokered by the United Nations, amid rising concern that the Islamic State extremist group is making further inroads in the country."We want to give a very strong push to counter the risk of expansion of Daesh," Gentiloni said, using an alternative name for the Islamic State. He said any agreement reached within Libya would later be supported by a UN resolution.Libya is locked in a civil war, four years after a NATO-backed revolt that overthrew long-time dictator Moamer Gaddafi. The oil-rich nation has two rival parliaments, backed by different militias competing for power.The conflict has allowed the Islamic State to gain a foothold in central Libya and has added to the numbers of migrants and refugees seeking to cross the Mediterranean to Italy.Ahead of the Libya talks, Rome is also to host a December 11-12 conference on conflicts and development opportunities in North Africa and the Middle East, with policymakers, businessmen and academics from the region and from Europe.