UNITED NATIONS, June 28 (Xinhua) -- Russian Ambassador to the United Nations Vassily Nebenzia said on Thursday he was "indignant and outraged" by the United States lowering its participation in a counter-terrorism conference underway at UN Headquarters.

The decision by UN Secretary-General Antonio Guterres to convene heads of counter-terrorism and law enforcement agencies "was taken in Washington as an encroachment on its alleged leadership in counter-terrorism efforts," said Nebenzia.

On Wednesday, the U.S. Mission to the United Nations issued a statement saying Washington was lowering its representation to the conference because representatives of civil society were not allowed full access, and blamed the action on "nefarious countries with no credibility on countering terrorism -- like Russia, Syria, Iran, Cuba, and Venezuela."

"We are not only disappointed in it but we are indignant and outraged by this statement," Nebenzia told reporters at a briefing.

The U.S. statement said civil society -- such as representatives of non-governmental organizations, indigenous groups, faith-based organizations, labor unions, charitable organizations, professional associations and foundations -- were bared from the first day's session, on Wednesday, but opened to the meeting Thursday.

U.S. Ambassador to the UN Nikki Haley said the United States had tried for months to get civil society into all meetings, but Nebenzia said she was late in her request.

Nebenzia said it was "very regrettable" the United States reduced its level of participation. "They need to participate jointly in counter-terrorism efforts."