On 7 October 1939 the Lithuanian delegation departed to Moscow where they later had to sign the Soviet -- Lithuanian Mutual Assistance Treaty due to the unfavorable situation .
Another large neighbor -- the Soviet Union also began preparing for the occupation of the Lithuania 's territory .
On 7 October 1939 the Lithuania delegation departed to Moscow where they later had to sign the Soviet -- Lithuanian Mutual Assistance Treaty due to the unfavorable situation .
Another large neighbor -- the Soviet Union also began preparing for the occupation of the Lithuania 's territory .