German diplomats had urged the Soviet Union to intervene against Poland from the east since the beginning of the war,[1][113] but the Soviet Union was reluctant to intervene as Warsaw had not yet fallen. The Soviet decision to invade that part of eastern of Poland which had earlier been agreed as the Soviet zone of influence was communicated to the German ambassador Friedrich Werner von der Schulenburg on September 9, but the actual invasion was delayed for more than a week.[112][114] The Polish intelligence became aware of the Soviet plans around September 12.