German Foreign Minister Heiko Maas told reporters at a news conference following talks with his Russian counterpart Sergey Lavrov on Thursday that the parties had failed to reach an understanding on the Skripal case, TASS reported.

"We also talked about the Skripal case," he said. "From our point of view, Russia has shown little willingness to take part in the constructive investigation of these acts. We reached no understanding here. We have different assessments, and we exchanged them."

Former Russian military intelligence (GRU) Colonel Sergei Skripal, who had been convicted in Russia of spying for Great Britain and later swapped for Russian intelligence officers, and his daughter Yulia suffered the effects of an alleged nerve agent in the British city of Salisbury on March 4. Claiming that the substance used in the attack had been a Novichok-class nerve agent developed in the Soviet Union, London rushed to accuse Russia of being involved in the incident. Moscow rejected all of the United Kingdom’s accusations, saying that a program aimed at developing such a substance had existed neither in the Soviet Union nor in Russia.