UNITED NATIONS: - United States U.N. Ambaddaor Zalmay Khalilzad Sunday accused Russia of seeking "regime change" in Georgia and waging "a campaign of terror" against the Georgian people, sparking a bitter verbal clash with his Russian counterpart in the Security Council, which again failed to agree on a truce call for the widening conflict. Reacting angrily to the U.S. Statement, Russian Ambassador Vitaly Churkin rejected the "terror" charge. "This is completely unacceptable, especially from the lips of a representative of a country whose actions we are aware of in Iraq, Afghanistan and Serbia," he retorted. Citing a telephone call between Russian Foreign Minister Sergei Lavrov and U.S. secretary of State Condoleezza Rice, the  U.S. ambassador accused Russia of attempting a regime change in Georgia. "This is completely unacceptable and crosses the line," Khalilzad said. "Russia must affirm that its aim is not to change the democratically elected government of Georgia and that it accepts that territorial integrity and sovereignty of Georgia." He also said through its military offensive against Georgia, Russia was trying to wage "terror" against the local people. "We must condemn Russia's military assault on the sovereign state of Georgia ... including the targeting of civilians and the campaign of terror against the Georgian population," he said. In a briefing to the council at Saturday's meeting, UN Assistant Secretary-General for Peacekeeping Operations Edmond Mulet said hostilities are continuing in Georgia and there have been a "substantial number of casualties, refugees and destruction. " Citing reports from UN peacekeepers in the region, Mulet expressed concerns that the conflict appeared to be spreading into Abkhazia. Since late Thursday, the council has been trying to adopt a statement that would call on the warring parties in Georgia to cease violence immediately. Belgian UN Ambassador Jan Grauls, the council's president this month, told reporters on Saturday it would be nearly impossible for the council to take any actions at the moment. "Regrettably I have come to the conclusion that it will be very difficult, if not impossible, to find common ground within the council on a draft statement to the press," Grauls said. The statement requires consensus and this has left the US with little choice but to move a resolution condemning the Russian action and calling for ceasefire despite Moscow having veto which could kill the resolution. But diplomats said if it gets a majority of votes, it would put a sort of moral pressure on Russia. Khalilzad said he would meet with his Western colleagues later to finalise the draft resolution that would call for "an immediate ceasefire and withdrawal of all forces to the status quo" in the breakaway Georgian enclave of South Ossetia. The meeting came as the United Nations said the conflict has spread to Abkhazia, another rebel enclave within Georgia. South Ossetia declared independence from Georgia in the early 1990s and was governed by a secessionist government since then although its independence has not been internationally recognized. On Friday, Georgian troops began a military action against South Ossetia's forces in an attempt to re-establish control over the region. In response, Russian troops moved into the region to fight the Georgian forces. Its warplanes also bombed the region. Russia said the two-day conflict has killed 1,500 people and the death toll is expected to rise.