UNITED NATIONS (Reuters) - Russia's new United Nations ambassador, Vassily Nebenzia, arrived for his first day of work at the world body on Friday, pledging Moscow's commitment to promoting peace, development and human rights.


Nebenzia succeeds longtime Ambassador Vitaly Churkin, who died suddenly in February of an apparent heart attack. Churkin, 64, had served as Moscow's U.N. envoy for more than a decade.


"Today the world faces unprecedented threats and challenges and Russia, as a permanent member of the Security Council, will continue contributing constructively to addressing those challenges together with the international community," Nebenzia told U.N. Secretary-General Antonio Guterres as he presented his credentials.


Russia, along with the United States, China, France and Britain, is a veto power on the 15-member Security Council.


Russia, Syria's most powerful ally, has vetoed eight resolutions, shielding Syrian President Bashar al-Assad's government from action during the more than six-year long war. China has backed Russia in vetoing six resolutions.


Nebenzia, a longtime Russian diplomat, also addressed the 193-member U.N. General Assembly for the first time on Friday, discussing counterterrorism.

(Reporting by Michelle Nichols)