Sochi: Biting US and EU sanctions slapped on Russia can be rolled back "if and when" the terms of a shaky Ukraine ceasefire are fully met, US Secretary of State John Kerry said on Tuesday.

After eight hours of talks with Russian leaders in the Black Sea resort of Sochi, including four spent in a meeting with President Vladimir Putin, Kerry insisted there was an "urgent need" for the United States and Russia to cooperate on confronting global challenges.

Lavrov for his part said that the meetings in Sochi helped the two countries to "better understand each other."

"Today`s meetings allowed us to better understand each other," Lavrov told reporters after the talks over Ukraine and Syria.

Lavrov added that "we have an understanding of the need to avoid steps which can inflict long-term damage on bilateral ties in various fields," Russia`s top diplomat said.

"Especially if we take into account the fact that the solution of many pressing modern problems depends on our well-coordinated joint efforts on the international arena."

Kerry, who was on the highest-level US visit to Russia since the conflict in Ukraine erupted in late 2013, had over four hours of talks with Lavrov and another four hours of talks with the Russian strongman.

Putin`s top foreign policy adviser Yury Ushakov told Russian reporters that the meetings were not a "breakthrough" but the manifestation of the first signs of understanding that the two great countries should return to normal cooperation."