WASHINGTON (Sputnik) – According to State Department spokesman John Kirby, Kerry held conversations with Hijab and de Mistura over the past two days.
"The Secretary expressed his deep concern about the deteriorating situation in Aleppo, where the [Syrian President Bashar] Assad regime continues to escalate the conflict by predominantly targeting innocent civilians and parties to the cessation of hostilities," Kirby said in a statement on Saturday.
The top US diplomat urged Russia to influence Damascus, according to Kirby.
"In the meantime, the Secretary made clear that we urged Russia to take steps to stop regime violations, especially its indiscriminate aerial attacks in Aleppo," he added.
Aleppo has recently been mired in violence and heavy fighting, despite the nationwide ceasefire in Syria. A mosque and a hospital have been destroyed earlier this week.
During the April round of Syria proximity talks, the HNC walked out over the continuous fighting in Syria and a lack of progress on humanitarian issues.
Kerry Considers Ending Violence in Syria's Aleppo Top Priority
US State Secretary John Kerry believes that putting an end to violence in Syria’s Aleppo, recently mired in heavy fighting, is a top priority, Kirby added.
"The Secretary made clear that ending the violence in Aleppo and returning ultimately to a durable, nationwide cessation is a top priority. We are working on specific initiatives to de-escalate the increased fighting and defuse tensions and hope to make tangible progress on such initiatives soon."
Russia and the United States brokered a "regime of silence" earlier that was implemented in the Damascus’ suburbs for 24 hours and in the northern Latakia province for 72 hours at midnight on April 30.
"In both calls, the Secretary underscored that the initial efforts to reaffirm the cessation of hostilities in Latakia and Eastern Ghouta are not limited to these two areas and that efforts to renew the cessation must and do include Aleppo," Kirby said.