Syria signalled on Friday that it is prepared to agree on prisoner exchanges and an Aleppo ceasefire ahead of the long-awaited Geneva II peace conference and the first meeting between the government and rebels seeking to overthrow President Bashar al-Assad, although the main western-backed opposition group struggled to decide whether to attend the talks.

Walid al-Mualem, Syria's foreign minister, announced in Moscow that he had asked his Russian counterpart, Sergei Lavrov, to help with "security arrangements" in Aleppo, the country's second city.

If successful a truce there could be used as a model for other parts of Syria, he said. Mualem also said that his government has agreed "in principle" to swap prisoners in exchange for people kidnapped by armed groups, but there would need to be an exchange of lists and a mechanism for implementation.

Russia has been pressing its Syrian ally to agree to ceasefires, humanitarian access and other confidence-building measures in advance of the UN conference, which is supposed to create a transitional government in Damascus but faces deadlock over the rebel demand that Assad step down.

Alongside its arm-twisting, however, Moscow appears to be backing Syria's insistence that the talks, due to be launched in the Swiss city of Montreux on Wednesday, should focus on combatting "terrorism" – which Assad says is backed by the west and Gulf Arab states.

Talk of Syrian readiness for humanitarian gestures appeared aimed at winning goodwill and securing tactical advantage rather than indicating a readiness for any substantive concessions to the rebels. Opposition spokesmen said they did not trust government ceasefire offers.