Mother Teresa, the frail and aging Nobel Peace Prize winner, gave up her retirement plans today when nuns from around the world re-elected her to head their order, a church official said. ``If this is God's will, I will serve in the capacity in the best way possible,'' the 80-year-old nun was quoted by Monsignor Francis Gomes as saying. He supervised the election. The Vatican gave its blessing and approval today to keeping Mother Teresa as head of the order she founded in the late 1940s. In March, Pope John Paul II bowed to Mother Teresa's wish to retire and accepted her resignation. He had rejected her earlier requests to step aside, even though she pleaded old age and ill health. The ballots were cast by 103 delegates representing the Missionaries of Charity around the world. The vote came after eight days of religious instruction, reflection and devotions conducted behind the walls of the Kennedy Center, a home for retarded women and children near Calcutta's Dum Dum Airport. The nun, known as the ``saint of the gutters'' for her work with the destitute and dying, suffered a nearly fatal heart attack a year ago. Sister Priscilla Lewis, spokeswoman for the order, said Mother Teresa's agreement to stay on was ``greeted with great joy and clapping.'' Gomes, who announced the result after a three-hour meeting, said the nuns felt that ``with so much opening up in the Western world and in the Eastern Europe they need someone who can face the challenges.'' Until the balloting outcome was announced, Mother Teresa had not changed her mind about stepping down, Gomes said. After the result was announced, Gomes walked to the center's front gate to give the news to a small group of reporters. Mother Teresa's re-election settles, for the moment, one of the biggest questions facing the Missionaries of Charity: who besides Mother Teresa has the worldwide recognition, coupled with the indefatigable determination and charisma, to open the political and financial doors needed to accomplish their work? At the height of the Israeli siege of West Beirut in 1982, she walked between the guns of the Israeli army and the Palestine Liberation Organization to rescue children trapped without food and medicine in a front-line hospital. The shooting stopped until her rescue mission was completed. Pulling herself from her sickbed only a few months after suffering a heart attack in September 1989, Mother Teresa headed for Moscow and Eastern Europe to open new missions. Her ministry to the poor and helpless began in earnest 43 years ago in the gutters of Calcutta. She gave up a comfortable teaching job at a Roman Catholic school to succor those whom no one else would touch. Rescuing dying people from the streets of the teeming metropolis, Mother Teresa went on to found a series of homes in Calcutta and eventually throughout the world for society's castaways. Today, the Missionaries of Charity operate 430 homes in 95 countries for lepers, cripples, abandoned babies and others with no place to turn. The order has about 3,000 nuns. She was awarded the Nobel Peace Prize in 1979. Mother Teresa was born in Skopje, Yugoslavia, daughter of an Albanian contractor.