Reformist Soviet leader Mikhail Gorbachev said Baroness Thatcher was a "heavyweight politician".
He said: "Thatcher was a politician whose word carried great weight. Our first meeting in 1984 set in train relations that were sometimes complicated, not always smooth, but which were serious and responsible on both sides.
"Human relations also gradually took shape, becoming more and more friendly. In the end we managed to achieve a mutual understanding, and that contributed to a change in the atmosphere between our country and the West and the end of the Cold War.
"Margaret Thatcher was a heavyweight politician and a striking person. She will remain in our memories, and in history."
More top news
The meeting indicates growing concern over deteriorating relations between the US and east Asian nation.
Mel B's estranged husband will be allowed to visit his young daughter - despite accusations of violence and links to the porn industry.
The singer, 70, has been forced to cancel several shows in the US as he recovers from the illness he contracted whilst abroad.