U.S. and Russia are close to reaching a deal to resolve a deadlock ahead of Syrian peace talks starting Monday, three Western and United Nations diplomats told Bloomberg. U.N.-sponsored talks over Syria have been delayed after the U.S. and Russia disagreed over which parties would be involved in the peace process.

After negotiations with U.S. and Russian diplomats, U.N. Special Envoy for Syria Staffan de Mistura is expected to invite two separate opposition delegations to the negotiations in Geneva, Bloomberg reported. Talks between the government of Bashar Assad and the opposition hit a roadblock in the last month after disagreements over which groups would be part of the opposition side.

U.S. Secretary of State John Kerry met Wednesday with Russian Foreign Minister Sergei Lavrov  to try to kick off the international talks on time and settle differences over which groups should be defined as terrorists and what to do with Assad. While the U.S. has backed-off from its earlier stance that Assad would have to leave Syria, Washington maintained that Assad cannot lead Syria over a long term, a position hotly contested by Russia.

The U.S., Russia and other nations have agreed on a timetable to form a transitional government in Syria by mid-2016 and hold elections in 2017. The talks, scheduled to open in Geneva Monday are part of the biggest international effort to resolve a civil war that in nearly five years has left more than 260,000 dead and forced millions from their homes in Syria.

According to Bloomberg, Russia had objected to the inclusion of a radical Islamist militia known as Army Of Islam, in the Saudi Arabia-sponsored opposition delegation endorsed by the U.S. It has demanded more of Moscow’s allies in the region be included in the negotiations, including Qadri Jamil, a former Syrian deputy prime minister, as well as Saleh Muslim, co-head of the Syrian Kurdish group PYD,

Under Saturday’s compromise, Russia has promised not to block the inclusion of Army of Islam in return for a separate delegation to be invited to the talks containing the opposition figures it has recommended.

Russian Foreign Ministry spokeswoman Maria Zakharova told Bloomberg she had no information yet about which opposition delegates will attend the talks in Geneva. A spokeswoman for de Mistura, Jessy Chahine, said a press briefing will be held Monday to provide more details.

On Saturday, Kerry reaffirmed that the U.N. would hold the talks on schedule and might invite representatives in addition to the main opposition delegation formed in Riyadh in December.

“We are confident that with good initiative in the next day or so, those talks can get going,” Kerry told reporters, according to Bloomberg.