A letter addressed by Soviet leader Joseph Stalin to the Communist leader of the Mongolian People's Republic has been put up for auction at Sotheby's, the auction house said on its website.

The typed letter, described by the New York auction house as "the utmost rarity", is countersigned by Soviet foreign minister Vyacheslav Molotov. It is expected to fetch $15,000-25,000.

In their letter, dated January 8, 1940, Stalin and Molotov ask Khorloogiin Choibalsan to provide the Soviet Union with 30,000 tons of sheep's wool, 8,000 tons of camel's wool, and 1,000 tons of goat's down to cloth etroops.

Sotheby's said the letter showed Stalin and Molotov were making preparations for a possible war with Germany.

"No doubt, they had learned a harsh lesson from the Finnish campaign of 1939 where the Soviet Army had been so poorly prepared for winter warfare," the website said.

A book of memoirs by Communist revolutionary and leader Leon Trotsky, called My Life: An Attempt at an Autobiography are also to be auctioned at Sotheby's. First published in 1930, the first year of Trotsky's exile, the book describes the author's childhood, the 1905 and 1917 revolutions, the Russian Civil War, Trotsky's split with Stalin, and his eventual expulsion from the Communist Party, the website said.

Trotsky was assassinated a decade later in Mexico by one of Stalin's secret police agents.

The book is estimated at $4,000-6,000.

NEW YORK, December 11 (RIA Novosti)