Russia on Saturday pushed its proposal for an international conference on Syria to include Iran, despite scepticism from the United States.

Russian Foreign Minister Sergei Lavrov was to give details on the plan for regional players to try to negotiate a strategy that would suit all Syrians at a briefing in Moscow at 1200 GMT.

Russia believes its idea of an international conference fits in with calls for international discussions by mediator Kofi Annan, deputy foreign minister Gennady Gatilov told the Interfax news agency on Saturday.

"In essence, what Kofi Annan is proposing is on the same track as the Russian initiative about calling an international conference on Syria," Gatilov said.

He added he saw no "fundamental difference," referring to Annan's call for a contact group including countries that hold influence both over the Syrian government and the opposition.

"It is necessary to mobilise the key outside players who have real effective influence on the various Syrian sides in order to induce them to completely fulfil Kofi Annan's peace plan."

Gatilov said that Tehran had "the full right" to attend such a conference, saying that Russia believed that "Iran's participation could play a constructive role in the search for a way to solve the Syrian conflict."

He reasserted Russia's opposition to further sanctions or the use of force in Syria in a bid to make President Bashar al-Assad's regime comply with Annan's plan.

"Introducing some restrictions or measures of force obviously will not promote this and will only exacerbate the already complex situation."

Russia, along with China, has vetoed two Security Council resolutions against Assad.

US special envoy Fred Hof visited Moscow on Friday for talks with senior diplomats but the discussions ended without Russia's signalling any change in its position on the crisis.