"The address of the American delegation which was prepared for the US Secretary of State – was a show, a show for millions of people and first of all for the mass media. It was a bad show because it was poor, scant and factless. And could be easily torn to tatters," Maria Zakharova said in an interview with the news channel Rossiya 24.
"Commenting on what John Kerry said today regarding Syria, I think that he just confessed that it is he who is living in a 'parallel universe'," added Maria Zakharova.
Speaking shortly after Sergei Lavrov, John Kerry also suggested that a cease-fire deal brokered by the US and Russia on October 9 could be "saved in spite of a string of violations."
Regarding the attack on the humanitarian convoy, the US Secretary of State went on to call for a ban on all aircraft over parts of the country to allow humanitarian aid to reach civilians.
"Supposedly we all want the same goal. I've heard that again and again," Kerry said. "But we are proving woefully inadequate in… making that happen."
He also said an attack on the humanitarian convoy on Monday raised "profound doubt" as to whether Russia and the Syrian government were committed to upholding the cessation of hostilities.
Maria Zakharova noted that the arguments provided by the US top diplomat did not "correspond to the facts", but admitted that the Russian Foreign Ministry has already got used to a "constant mismatch" in the facts provided by the American side, reiterating that John Kerry was "trying hard for the mass media."
Meanwhile, Russian political expert Victor Murakhovsky has said that the US rests it claims on incomprehensible proofs provided by some "not quite healthy people".
"I do not believe that there were any experts on the ground who were able to immediately identify that it was Russian SU-24 [attacking the convoy]. It is ridiculous," Murakhovsky told Russia's online newspaper Vzglyad.
He urged to be very cautious when reading through such "bogus stories" posted in the social media as they come from "not quite healthy people".
However the US "buys it", the expert said, reminding of a recent case when some Russians have supplied the US intelligence with fake messages about special military trains and military equipment.
Victor Murakhovsky also noted that judging by the pictures from the site of the attack, there were no air bombs or otherwise artillery shells used in the attack as there were no bombed craters left afterwards. However at the same time, there were cars damaged by splinters.
"It might be mortar shells or projectiles, self-made by the militants," he noted, adding that such projectiles are often made from gas cylinders with jet engines.
Such projectiles, he said, had been used by Palestinians during their attacks on Israel from Gaza Strip.
The political analyst also added that a military expert on the ground will be able to identify what exactly had been used for the attack by studying the splinters, all the rest is "proofless rumours".
Israeli political analyst and former high-ranking representative of the Israeli intelligence Yakov Kedmi is also not inclined to believe the accusations of the US.
"If the humanitarian convoy was really attacked by Russian SU-24 as it is claimed by the US, let the US provide the proofs," he told the website.
"The situation in Syria is being controlled with the satellites and it won't be a problem to find the convincing proofs if there are any," he added.
The expert added that in its turn, Russia's Defense Minister knows only too well that there were no Russian jets in the area and the western officials do not treat the US claims seriously.
"The claim of an anonymous source in Pentagon is of propagandistic character. May be some journalists will take up the claim but it won't affect the situation on the ground," he told the website.
Meanwhile Middle East expert Andrei Baklanov noted that the whole process of Russia-US negotiations on Syria is being complicated by the US reluctance to reveal the details of the ceasefire agreement.
He further suggested that it could be caused by the US unwillingness to separate radical Islamists from the so-called "moderate opposition."
"Thus they are unwilling to reveal their tricks," he told Russia's Gazeta.ru online newspaper.
He said that it is highly unlikely that the ceasefire agreement could contain any secret details on Assad's fate, for example.
"I am convinced there are no agreements on Assad, I do not believe in it," he told the newspaper.
Even if there are any agreement on the further fate of the Syrian president, he suggested, they would have hardly put on paper. Such agreements are usually made verbally.
The expert also said that the parties to the agreements will be hardly able to agree on renewal of the cessation of hostilities as the "lack of trust among the parties destroys the accords".
Even though he highly appreciates the professional qualities of John Kerry, the expert notes that it look as if the US Secretary of State is "acting on his own, without any support from Pentagon."