Congress President Sonia Gandhi on Wednesday mourned the death of former Israeli President Shimon Peres, saying he gave strength and goodwill to Indo-Israeli relationship.Describing him as a defining political figure, Gandhi said in a condolence message that Peres would be remembered as a steadfast pacifist and a believer in peace and coexistence. She said Peres' tenure as Israeli President added strength and goodwill to Indo-Israeli relationship. Peres, 93, a Nobel laureate and one of Israel's founding fathers, died on Wednesday.