DUBAI, Dec 11 (Reuters) - Norway said it would donate an additional $50 million to Brazil's Amazon Fund to promote conservation of its rainforest region, the Nordic country's first new donation since the fund was frozen by right-wing Jair Bolsonaro in 2019.

Brazil and Norway announced the donation at the United Nations COP28 climate change summit in Dubai. Deforestation is the largest source of Brazil's planet-warming greenhouse gas emissions.

As one of his first acts as Brazil's new president, Luiz Inacio Lula da Silva reopened the Amazon Fund to protect the world's largest rainforest.

But the fund can only receive donations when Brazil lowers deforestation. Under Bolsonaro, forest destruction had hit a 15-year high.

Lula has aggressively stepped up the enforcement of environmental laws since assuming, slashing deforestation rates.

Norway made the donation in recognition of deforestation falling by roughly 50% in the first 11 months of the Lula administration, Brazil's Environment Ministry said in a statement.

"Brazil has a commitment to zero deforestation by 2030 and Norway's support is essential," Environment Minister Marina Silva said.

Bolsonaro's government had shuttered the Amazon Fund, citing unspecified irregularities with NGOs who received grants and providing no evidence.

Norway is by far the fund's largest donor, having given about 3 billion reais ($606.13 million) before it was frozen.

Since Lula's government came into office, an additional 4 billion reais has been pledged to the fund with donors including the United States, United Kingdom, Germany, Denmark, the European Union and Switzerland.

($1 = 4.9494 reais) (Reporting by Jake Spring; editing by David Evans)