Internationally brokered talks between the Syrian government and opposition groups are scheduled for January 25 in Geneva, though the United Nations said they might be delayed. A UN envoy on Wednesday said pressure must be put to make sure negotiations take place, even as United States Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov met to discuss the matter in Zurich. Kerry and Lavrov have said Geneva talks will take place as scheduled, though no decision was taken on which country will represent the opposition.

A Syrian opposition council supported by Saudi Arabia said it would not attend talks if a third party enters negotiations, Reuters reported. Dates will be confirmed by the UN on the advice of its special envoy Staffan de Mistura. De Mistura said he thought Russia “has a great vested interest in not getting involved for too long” and that the US was also “heavily involved politically”. Russia has been carrying out air strikes on Syria since the end of September.

A coalition led by the United States has been carrying out strikes against Islamic State militants in Syria, and has decided to further intensify its attacks in both Iraq and Syria, according to reports. The crisis is entering its sixth year now, with humanitarian groups appealing for peace as civilians continue to die in both countries.