UNITED NATIONS, Jan 20: Under pressure from Israel and the United States, UN Secretary General Kofi Annan has decided not to reappoint the head of United Nations relief agency for Palestinians, UN officials said on Wednesday.

Peter Hansen has led the UN Relief and Works Agency (UNRWA) since Feb 1996 and had signalled he was willing to serve a fourth three-year term at its helm, but Israel opposed his appointment and persuaded US to oppose his reappointment.

"It was clear that he wasn't renewed because of US and Israeli calls for his head," said one official familiar with the deliberations, said. The United States was the only member of the eight member advisory board opposing Mr Hansen's reappointment, one UN official said, adding that European Union and Arab nations backed him for a new term.

According to some UN officials, Mr Hansen's departure had been in the works for some time as Israeli unhappiness with him built up over the years. Israel has repeatedly called for his resignation. Mr Annan told reporters on Monday Hansen was among a number of UN officials who would be leaving their posts.

Mr Hansen was often stopped by the Israeli military from going in and out of Gaza and this was "not doing any good to the agency," said one UN official. He has often sparred with the Israelis over the agency's work.

The Jewish state accuses UNRWA of turning a blind eye to the use of its vehicles and facilities by militants waging a four-year-old uprising. Mr Hansen in turn has accused Israel of wanton destruction of Palestinian homes, which Israel denies.

In one dispute in October, Israel said militants had transported a Qassam rocket in an UNRWA ambulance, a charge that proved false after videotape shot by an Israeli drone aircraft showed the object to be a stretcher.

That prompted Mr Hansen to accuse the Israeli government of disseminating "deliberately inciteful, false and malicious propaganda." In another fight, Israeli UN Ambassador Dan Gillerman complained to Annan after Hansen said his agency did not exclude Hamas militants from working for it.

Mr Hansen told the Canadian Broadcasting Corp: "Hamas as a political organization does not mean that every member is a militant and we do not do political vetting and exclude people from one persuasion as against another."

The Bush administration made clear it would be hard to keep up the $120 million annual US contribution to the agency if Hansen were re appointed due to unhappiness over him in Congress, the officials said.