Peres took the oath of office in parliament less than three weeks shy of his 84th birthday, replacing disgraced Moshe Katsav in the largely ceremonial post for a seven-year term as Israel's ninth president.

His landslide election by the Knesset as head of state was the first vote for a top office that he has won despite having held just about every senior position in the Jewish state.

As he bid good-bye to the chamber where he has sat for the past 48 years, Peres promised to serve as president for all of the nation's citizens and to keep up efforts toward peace with the Palestinians.

"I am no longer the messenger of a party but a trustee of the nation, of all the citizens of the state ... (who) must encourage the peace process. Within the house. With our neighbours. In the whole region."

He pledged to work to make sure Israel's non-Jewish citizens did not face discrimination.

"If they do not enjoy complete equality, we will not be at peace with ourselves and with our fellow men.

"Israel ... must be a good and warm home for Jews who are not Israelis, as well as for Israelis who are not Jews."

He said he would also work on Israel's relations with the diaspora, and said Israeli development priorities should include Jerusalem, the Negev, the Galilee and the Jordan valley alongside with Jordan and the Palestinians.

"My eyes have seen Israel in its most difficult hours and also in moments of achievement and spiritual uplifting.

"It is true that in the picture stains also appear. It is true that we have flawed and have erred, but please believe me -- there is no room for melancholy."

Supporters say the international prestige of Peres, who up to now has been admired abroad far more than at home, could lift the presidency from a disgrace heaped upon the office after his two predecessors were ousted by scandal.