"There are many issues on the agenda and the presidents will discuss what they believe to be necessary," Lavrov said, as aired on Rossiya 1 broadcaster.
"Circumstances keep changing for our US colleagues, we might also have some changes. So there are no concrete agreements at the moment, we cannot say anything with certainty," Peskov told Rossiya 1 broadcaster. The Kremlin spokesman added that the number of issues on bilateral agenda kept growing.
Peskov stressed that "deficit of mutual trust" in the relations of the two countries was growing amid delays in preparation of the Putin-Trump summit.
Meanwhile, Both Russia and the European countries are alarmed by the unclear future of the Russian-US Intermediate-Range Nuclear Forces (INF) Treaty, Dmitry Peskov said late on Sunday.
In October, US President Donald Trump said that Washington intended to leave the INF Treaty, accusing Russia of violating it numerous times, while the Kremlin rejected the accusations, adding that Russia would be forced to take measures to ensure its security if the treaty was terminated by the United States.
The INF Treaty is an agreement that the United States and the Soviet Union signed in December 1987. It prohibited either country from possessing, producing or flight-testing ground-launched ballistic and cruise missiles with a range of 500 to 5,500 kilometers (311 to 3,418 miles) and their launchers.