UNITED NATIONS, Feb. 23 (Xinhua) -- UN Secretary-General Antonio Guterres said here Thursday that he was encouraged by the fact that the Syrians came to Geneva and sat together in the same room earlier in the day to continue their peace talks.

"After six years of bloodshed, the secretary-general urges the Syrians who have accepted the invitation to be in Geneva to engage in good faith as the special envoy seeks to facilitate the process," said a statement issued here by Guterres' spokesman.

UN Special Envoy for Syria Staffan de Mistura formally kicked off a fourth round of Syria talks in Geneva on Thursday in an opening session that brought the opposition and government delegations face-to-face at UN headquarters in Geneva.

The secretary-general commended the work of his special envoy.

"He appreciates the presence of the members of the Security Council and the International Syria Support Group at today's welcoming, and underlines the importance of international unity behind the UN-led political process in the weeks and months ahead," said the statement.

"While acknowledging that progress will not be easy, the secretary-general believes strongly that only a political solution can bring peace to Syria and that all those Syrians who have committed themselves to this goal should redouble their efforts for peace," the statement added.

The last time the warring parties were convened in Geneva was in April last year. The talks were put on hold amid a humanitarian meltdown and systemic violence in the Middle East country.

Two rounds of talks also took place between the Syrian government and rebels in Kazakhstan's capital Astana last month and this month.

The Syrian conflict, which began in March 2011, have left an estimated 400,000 people dead and millions displaced.