WASHINGTON (Reuters) - The United States is "very, very concerned" about an increase in Syrian violence just ahead of planned peace talks in Geneva this week, a State Department spokesman said on Monday, blaming Syrian government forces for the escalation in fighting.
"We are very, very concerned about the recent increase in violence and that includes actions that are in contravention of the cessation of hostilities," spokesman Mark Toner told a news briefing.
He said Secretary of State John Kerry conveyed the U.S concerns in a phone call with his Russian counterpart, Sergei Lavrov, on Sunday.
"We would say that the vast majority of violations have been on the part of the regime," Toner said when asked who was to blame for violations.
Kerry wanted to make sure that in the next days leading up to peace talks "every extra effort is made in order to sustain and solidify the cessation of hostilities," Toner said.
Washington's worries come as the Syrian army appeared to send reinforcements to the ancient city of Aleppo, threatening a fragile truce in the run-up to the second round of peace negotiations.
The ceasefire was agreed in February between the United States, which backs Syrian opposition groups, and Russia, which together with Iran supports the Syrian government.
U.N.-sponsored talks aimed at ending the five-year conflict are meant to resume on Wednesday. The first round made little progress with no sign of compromise over the thorniest issue, the fate of Syrian President Bashar al-Assad.
Toner said the United States wanted to make sure that opposition forces were not attacked as the Syrian army seeks to take Aleppo.
"If they are attacking members of the Syrian opposition who have signed on to the cessation of hostilities, then those are violations of the cessation of hostility," Toner said, adding: "We need greater clarity what is actually planned, who are they targeting."
(Reporting by Lesley Wroughton; Editing by Nick Zieminski and Tom Brown)