Syrian and Russian aircraft pounded rebel-held areas of Aleppo, a monitor said, after the army announced a new offensive aimed at retaking all of the divided second city. Kerry said the United States and allies who supported opposition groups were prepared to reciprocate but only if Russian Federation showed it was serious about implementing the ceasefire agreement.
Another setback for the ceasefire came on September 19 when unknown attackers hit a United Nations convoy heading to Aleppo.
The Syrian army announced on Monday the end of the week-long ceasefire, without extending it, as part of the Syrian government dismay with the US -led attack against Syrian military positions in Deir al-Zour earlier this week, which killed 90 Syrian soldiers, and the violations the rebels were said to have committed during the truce time.
Russian Federation and the USA support Syria's government and opposition respectively.
"Today we are sending an inter-agency, cross-line convoy with urgently needed aid to people in a besieged area of rural Damascus", United Nations humanitarian agency (OCHA) spokesman Jens Laerke said in a statement.
Russian Federation and Syria said they did not have anything to do with the attack but a new agreement for a longer ceasefire now seems to be even more hard to achieve.
Russian Foreign Minister Sergey Lavrov speaks during a Security Council Meeting September 21, 2016 on the situation in Syria at the United Nations in NY.
US Secretary of State John Kerry met his Russian counterpart Foreign Minister Sergey Lavrov on Thursday for a crisis meeting of governments with a stake in the Syrian civil war.
That's what they should accuse first: "the people or the militants, the terrorists who are responsible for the security of this convoy", Assad said.
But even as Kerry vowed to press on with all efforts to find a peaceful solution to the war between Syrian President Bashar Assad's Russian-backed government and US -backed rebels, the American acknowledged the current strategy wasn't working.
A man runs with a stretcher at a damaged site after air strikes on the opposition-held al-Qaterji neighbourhood of Aleppo, Syria September 21, 2016.
"The offensive on Aleppo just shows why we need Syrian planes grounded, otherwise there will be no truce", Mr Ayrault said.
"We believe that the publishing of these documents will contribute directly to their implementation and the way toward the Syrian settlement", the diplomat went on to say.