Citing administration officials, The Washington Post reported on Thursday that Trump has ordered his administration to prepare a push for a new arms control agreement with Russia and China due to the mounting cost of the 21st-century nuclear arms race.
Ushakov, in remarks to Russian state TV released on Sunday, said Moscow was ready to hold talks about the subject.
"Firstly, what exists already (by way of arms control agreements) needs to be honored," said Ushakov. "We are also ready for new ones, but for that serious negotiations are needed and unfortunately so far nobody has embarked on any."
Ushakov's words were more upbeat than those of a Kremlin spokesman who on Saturday dismissed Trump's proposals on nuclear arms disarmament as "not serious."
Relations between Moscow and Washington are strained and both countries have said they are quitting the 1987 Intermediate-range Nuclear Forces (INF) Treaty, stoking fears of a wider arms race.