Ashton's office issued a statement expressing concern over recent violence from the rebel March 23 Movement in eastern DRC.
M23 seized Goma, the provincial capital of North Kivu province, briefly last year. The U.N. peacekeeping mission in DRC, known by its French initials MONUSCO, said civilians were killed and peacekeepers were injured during renewed violence in the area.
Ashton said she condemned the use of heavy weapons by M23 against targets in Goma, noting the conflict appeared to be spreading across the shared border into Rwanda.
"[Ashton] calls on all parties involved to exercise restraint in the interest of the civilian population and in support of a political solution to the crisis in the east of the DRC," the Wednesday statement read. "She reiterates that there is an urgent need for the M23 and armed groups to lay down their arms."
U.N. special envoy to DRC Martin Kobler told German broadcaster Deutsche Welle residents in Goma were protesting against U.N. peacekeepers, who have a mandate to use force. He attributed the demonstrations to a sense of frustration with the security situation in eastern DRC.
Ashton said the European Union supports the MONUSCO mandate for an intervention brigade tasked with ensuring the protection of civilians in DRC.