The ninth round of Syria peace talks sponsored by Iran, Russia, and Turkey began on May 14 in Kazakhstan’s capital, Astana.
Kazakh Foreign Ministry spokesman Anuar Zhainaqov told reporters that UN Special Envoy for Syria Staffan de Mistura is expected to join the negotiations in Astana later in the day and a Syrian armed opposition delegation should arrive there on May 15.
Zhainaqov added that the United States was not taking part in the talks.
In the past, the United States sent a delegation to the talks.
Russian presidential envoy for Syria Aleksandr Lavrentyev said on May 14 that Moscow still hopes Washington would take part in the talks.
"We are hoping that common sense will prevail and they [the United States] will take part in our session," Lavrentyev said.
Besides the Astana talks, United Nations-sponsored negotiations have been held in Geneva in search of an overall political solution to end the seven-year civil war in Syria.
Representatives of the Syrian government and some rebel groups attend the sessions, and the United Nations and Jordan generally send observers.
Russia and Iran back the government of Syrian President Bashar al-Assad, while Turkey, along with the United States, supports differing rebel groups.
More than 330,000 people have been killed in Syria and millions have been driven from their homes since the conflict began in March 2011 with a crackdown on antigovernment protests.