US Secretary of State John Kerry has said he is confident Syria's opposition National Coalition will attend upcoming peace talks in Switzerland.
"I am confident personally that the Syrian opposition will come to Geneva," Kerry said after a meeting of the 11-nation "Friends of Syria" group that was attended by Coalition leader Ahmad Jarba.
The bloc is under intense pressure to confirm its participation in the talks, scheduled to begin on January 22, and has said it will decide on the issue next Friday.
The Friends of Syria, an alliance of mainly Western and Gulf Arab countries who support the opposition, earlier on Sunday stated that the conference, bringing regime negotiators and opposition groups together, is necessary to solve the crisis.
"There is no other political solution," French Foreign Minister Laurent Fabius said, speaking on behalf of the group. "There will be no political solution for Syria unless Geneva 2 meets."
Kerry reiterated that there is "no military solution" to the conflict, which has killed more than 120,000 people since the uprising against President Bashar al-Assad's regime began in March 2011.
In a joint statement, the Friends of Syria nations - US, Britain, France, Germany, Italy, Turkey, Saudi Arabia, the United Arab Emirates, Qatar, Egypt and Jordan - urged the Coalition to attend the upcoming talks.
"We invite them to form, as soon as possible, a delegation of opposition forces to participate in the political process," the statement said.
Al Jazeera's Jacky Rowland, reporting from Paris, said there was nothing said in public by the Syrian opposition during the course of the meting that would actually back up the confident assertions made by Kerry.
"It is by no means certain that the Coalition is ready to say 'yes' to that invitation," she said.
Coalition leader Jarba said earlier that the international alliance had agreed that Assad and his family will have no role in the country's future.
"We are all in agreement to say that Assad has no future in Syria," he said.
The Syrian regime has said that it will attend the conference in Switzerland but that Assad stepping down is not an option.
On the ground in Syria, regime troops have started moving towards rebel positions on the outskirts of Aleppo city, including the strategic district of Sheikh Najjar.
The territory is the main point of entrance into the rebel-controlled east, and by taking it, the government could effectively block supply lines from Turkey, Al Jazeera's Zeina Khodr said on Sunday.
|Al Jazeera's Zeina Khodr reports from Beirut
"The rebels are bogged down in their own war in the opposition-held north and the regime is trying to push forward, trying to make advances," our correspondent reported from Beirut.
Activists said the army was also attempting to push towards a strategic highway linking the airport to the western part of city, which remains under government control.
The government's push comes amid fierce infighting between various armed opposition groups, primarily directed against al-Qaeda-linked fighters in the Islamic State of Iraq and the Levant (ISIL).
At least 700 people have been killed in the past nine days as rebel forces turned on each other, while dozens of fighters from both sides were kidnapped, the Britain-based Syrian Observatory for Human Rights said.