Russian Foreign Minister Sergey Lavrov's comments, in which he announced his country’s rejection of security guarantees for Ukraine if they are built with the logic of isolating Russia, have in effect derailed Russia's negotiations with the US, said a European official familiar with the situation, Bloomberg reports.

According to the source, the Kremlin may now try to convince the White House to abandon its insistence on security guarantees for Ukraine and lower the level of the meeting between Russia and Ukraine from the presidents of these countries “to a meeting with lower-level officials to avoid new US sanctions.”

Several high-ranking European officials and diplomats, who wished to remain anonymous, stated that they viewed Lavrov's comments as an attempt to slow down the process, and expressed doubt that Russian President Vladimir Putin was ready to conclude a deal.