GENEVA (Reuters) - Syria s opposition wants Russia and other states to put pressure on President Bashar al-Assad to engage in peace talks in Geneva to produce a political solution within six months, the chief of its delegation said at the start of negotiations on Wednesday.  We want more pressure on the regime to engage in the negotiation and continue in the negotiation to reach a political solution in six months, as (U.N. Security Council Resolution) 2254 says,  Nasr Hariri told Reuters.  Just speaking about a political transition without any advancement, we will lose our trust in the process and our people will lose their trust in us and in the process itself.  Hariri said Syria and its ally Iran wanted the fighting to continue until they could declare a military victory, and they were not abiding by agreements to de-escalate the fighting in areas such as Eastern Ghouta, a besieged rebel-held enclave.  If the situation continues as it is now I think there is great danger in these agreements.   Russia had arranged a pause in the fighting for Eastern Ghouta for two or three days, which showed Moscow had the power to ensure de-escalation agreements were respected, he said.  A war monitor and a witness said on Wednesday that heavy shelling hit Eastern Ghouta in spite of the start of the Russian-backed truce there. Syria s civil war is now in its seventh year and previous rounds of negotiations made virtually no progress, with no direct contact between the opposing delegations, who took turns to meet U.N. mediator Staffan de Mistura. The Syrian government delegation has always rejected the opposition s demand that Assad leave power, calling them  terrorists  who lacked the legitimacy to negotiate. The government s position on the battlefield has strengthened dramatically since Russia joined the war on Assad s behalf two years ago, raising speculation that the opposition could soften its negotiating stance. However, opposition delegates meeting last week issued a statement repeating their demand that Assad be excluded from any transitional government, a position which Damascus and its allies say is divorced from reality on the ground. De Mistura originally planned a round of 4-5 days but was now planning to continue until Dec. 15, Hariri said, adding that his team had come hoping for direct talks with the government delegation for the first time. Hariri said his opening words to government negotiator Bashar al-Ja afari would be:  I hope despite all of the crimes which have been done in Syria, I hope that the regime can come ready to put the people of Syria first.  De Mistura has asked both sides to come without preconditions. Hariri said the opposition had no preconditions, but planned to talk about Assad s future as part of the negotiations. The talks are meant to cover four major issues: elections, governance, the constitution and fighting terrorism. All four would be discussed, Hariri said, but it would not be possible to go straight into the core elements straightaway.   If we will speak about constitution or election under the current circumstances inside Syria with this kind of regime, I think it will be impossible,  he said. Among issues the opposition wanted to discuss at the outset were humanitarian aid and people detained by forces loyal to Assad. Hariri said detainees number more than 200,000. Syrian government negotiator Ja afari also met de Mistura on Wednesday but declined to speak to reporters afterwards. 