Moscow to Kerry: Liar

And it's not about lying that he wasn't on his yacht.
From Reuters:

Russia blames Syria rebels for Aleppo chemical attack

Russian scientific analysis indicates a deadly projectile that hit a suburb of the Syrian city of Aleppo on March 19 contained the nerve agent sarin and was most likely fired by rebels, Russia's U.N. envoy said on Tuesday.

The incident at Khan al-Assal in the northern province of Aleppo killed more than two dozen people. Both the government and rebels have blamed each other for what they say was an attack involving chemical weapons. Both sides also deny using chemical weapons.

Moscow's U.N. ambassador, Vitaly Churkin, said Russian experts visited the location where the projectile struck and took their own samples of material from the site. Those samples, he said, were then analyzed at a Russian laboratory certified by the Organization for the Prohibition of Chemical Weapons....MORE

From what I understand, this is not how diplomacy is done. Realpolitik, yes but not diplomacy.
To reprise a line from a couple weeks ago:

I really wish we had someone with balls talking to Putin. Hillary maybe.