Cheers rose alongside the red, black, white and green flag during a ceremony held in the rain.
“This is truly a historic moment,” Palestinian President Mahmoud Abbas said at the ceremony, his speech punctuated by rousing applause and standing ovations.
“We hope this will be a good auspice for Palestine to become a member of other organizations,” he said.
Palestine was admitted as a member of the UN Educational, Scientific and Cultural Organization in an October vote that prompted the US to cut off funds to the agency.
Two US laws required the halt in the flow of funds to the agency, forcing it to scale back literacy and development programs in countries such as Iraq, Afghanistan and the new nation of South Sudan.
The Palestinians also are seeking full-fledged UN membership, but Washington has threatened to veto that move, saying a negotiated settlement with Israel should come first.
US officials have said UNESCO’s decision risked undermining the international community’s work toward a comprehensive Middle East peace plan, and could be a distraction from the aim of restarting direct negotiations between Israel and the Palestinians.
The United States contributes $80 million annually in dues — 22 percent of UNESCO’s overall budget — and its 2011 contribution was not yet in when the laws took effect, immediately throwing UNESCO into crisis.
Several countries are lobbying the US to renew its funding.
UNESCO is known for its program to protect cultures via its World Heritage sites, but its core mission also includes activities such as helping eradicate poverty, ensuring clean water, teaching girls to read and promoting freedom of speech.
