Russia and the US are to reopen negotiations about reducing their nuclear warheads, presidents Dmitry Medvedev and Barack Obama have said.
The discussions will be the first such talks for more than a decade.
Mr Obama said earlier there were very real differences between Washington and Moscow, but that there was also a broad set of common interests.
The announcement came on the fringes of the G20 summit of world leaders which is convening in London.
Mr Medvedev has invited his American counterpart to visit Moscow in July - an invitation Mr Obama has accepted.