UNITED NATIONS -- The suspension of US foreign aid has harmed UN humanitarian operations in the Democratic Republic of the Congo (DRC), a senior UN official said Tuesday.

"The security and humanitarian situation in the eastern DRC remains extremely volatile," with escalating armed clashes, mass displacement and increasing insecurity in both North Kivu and South Kivu provinces, said Bruno Lemarquis, deputy special representative of the UN secretary-general, resident coordinator and humanitarian coordinator for the DRC.

The US suspension of foreign aid "is having a major impact" on humanitarian aid operations in the country, Lemarquis told reporters via video from the capital Kinshasa.

The dependence on US funding "means a lot of programs had to shut down on everything we are doing. So, it's emergency health, it's emergency shelter," he said, adding that coordination capacity in his office had to halt.

"This is a major source of concern with several UN agencies and international NGOs active on the ground having seen their operations at best severely impact, if not halted," he said.

Lemarquis said the only exception so far was emergency food assistance, calling for more exceptions from Washington and urging the international community to intensify support for the humanitarian response in the country.

Since Jan 26, more than 3,000 people have been reportedly killed, 2,880 injured and over 500,000 displaced, adding to the 6.4 million already internally displaced people in eastern DRC, according to the United Nations.