GENEVA — The embattled chief of the U.N. weather agency was reelected yesterday and immediately pledged to deal with natural disasters, climate change, and other issues now that he has imposed major reforms following an embezzlement scandal.

The 188-nation governing congress of the World Meteorological Organization agreed by acclamation to give Michel Jarraud, who ran unopposed, for a second four-year term.

“I’m very encouraged and very pleased by the strong support of the member states,” Mr. Jarraud told the Associated Press. “Obviously, the challenges are there — natural disasters, climate, water — and I’m even more determined now to address them.” A top goal is improving global forecasting and warning systems to help minimize disasters, he said.

Mr. Jarraud’s fortunes appear to have turned only four months after a confidential internal audit surfaced suggesting that some of the $3.5 million stolen by a former employee was used to influence votes in the 2003 election he won for a first term. The 53-year-old French meteorologist, who was the agency’s no. 2 at the time, maintains he was uninvolved in any wrongdoing but concedes that the controls were lax.

“They’ve come a long way,” the top American representative to WMO and head of the agency’s new watchdog Audit Committee, retired Brigadier General J.J. Kelly, said. He praised Mr. Jarraud for steps taken since 2004 to avoid fraud, including new audit procedures. Swiss investigators have recovered $300,000 of the missing money and returned it to the agency, Mr. Jarraud said.

But the agency is not in the clear. Earlier this month, the Swiss investigation was widened to include allegations of vote-buying, the general prosecutor of Geneva, Daniel Zappelli, said. He added that WMO’s cooperation had been good so far.

A former agency auditor, whose internal audit concluded much of the money was used to influence votes of about 50 delegations during the agency’s May 2003 election, has sued Mr. Jarraud and the WMO after she was fired in 2006. Maria Veiga of Portugal, who says her firing was direct retaliation for her investigation, also has challenged her dismissal through the United Nations.

Meanwhile, the U.S. Government Accountability Office is considering a request from members of Congress to investigate, General Kelly said. Mr. Jarraud said WMO has agreed to waive his diplomatic immunity and that of about 10 officials sought for questioning. “We’re really committed to cooperate,” he said.

Mr. Jarraud said that after Swiss authorities took over the case in 2003, they issued an arrest warrant for the then chief of the fellowship program in WMO’s training department, Muhammad Hassan of Sudan. Authorities said he left Switzerland after the discovery that the money was missing and that his whereabouts are unknown.