Syria\'s main opposition group in exile said here Thursday that it would not take part in the Geneva peace talks aimed at drawing up blueprint of a political solution to the Syrian crisis. Speaking at a news conference here in Istanbul, George Sabra, head of the Syrian National Coalition (SNC), said that the opposition was suspending their assent to participating in the talks until the international community intervened to end a siege by the Syrian troops as well as foreign fighters on the border town of al-Qussair. \"The National Coalition will not take part in any international conference as long as the militias of Iran and Lebanese Hezbollah continue their invasion of Syria,\" Sabra said. For his part, Khaled Saleh, the SNC spokesman, said that civilians in Qusair had been \"severely wounded\" and the city had been completely cut off by forces loyal to President Bashar al- Assad. \"Civilians have no access to water, electricity and the massacre goes on while the Assad regime continues to use weapons,\" he added. Saleh called on the UN and the Arab League to intervene to stop the killings that \"Hezbollah is responsible for.\" On Wednesday, the SNC said it would participate in the Geneva talks only if there was a timeframe for adopting an international agreement that would lead to the ouster of al-Assad. The planned conference will tackle the recent U.S.-Russian efforts to explore political options for resolving the long- standing stalemate in the conflict-stricken country. The conference aims to revive a previous meeting held in June 2012 in Geneva and sponsored also by the two major powers. However, last year\'s conference called for an immediate ceasefire between Syrian fighting parties and a dialogue on a transitional government. The outcome of the meeting was fruitless as it couldn\'t be implemented on the ground.