The so-called Syrian National Coalition released a statement early on Monday, in which they outlined conditions that must be met before the talks.
The opposition wants a transitional government in any condition after talks, release of political prisoners and access of relief agencies to besieged areas.
The opposition has been blaming the Syrian government for not allowing access to some areas that have been occupied by their own militants.
This is while the militant groups in Syria usually attack an area and take all residents as hostage.
Not only they deter army improvements in those areas but also recieve humanitarian supplies sent to people, which they usually seize and impose strict conditions for spreading them.
"The oppositions’ request asked for an end to the fighting, withdrawal of Syrian armed forces from major cities and discussed an urgency of the introduction of humanitarian aid," Qatari Al Jazeera news channel reported from Istanbul, where the SNC was meeting.
The main sticking point continued to be centered on the role of Bashar al-Assad, with the opposition demanding that Syria’s president not have any part in the country's future.
Assad, who has been dealing with a massive foreign-charged insurgency with thousands of militants entering his country to topple the government, has repeatedly said that he cannot leave the country in such ravaged condition.
The government has been asking the opposition to lay out its plan for future of the country, in a condition that they had al-Qaeda-linked groups fighting at their side and now their leaders wants a ruling system of their own in Syria.
Al-Qaeda which has the strongest armed groups on the ground in Syria, including al-Nusra Front and the Islamic State of Iraq and Levant, has already announced its intentions for setting up a caliphate with their own version of law.
The deeply divided Syrian National Coalition reached a decision for attending the Geneva 2 conference after two days of discussions in Istanbul.
The coalition has been more concerned about Assad leaving instead of the bloody conflict that is taking tens of lives every single day.
It has also refused several international calls to announce truce even on National and religious holidays.
"All we can do is hope is that these talks will end with the departure of Bashar al-Assad," said Adib Shishakly, a member of the coalition.
Russia and Western nations are pushing for new talks between the Syrian government and militants on a negotiated solution to the conflict, which has killed more than 115,000 people since March 2011.