The European Parliament urged the European Union on Thursday to freeze direct budget support for Rwanda until it breaks links with Tutsi-led M23 rebels and allows humanitarian access to areas of the Democratic Republic of Congo where they advanced.

M23 now controls nearly all of North Kivu and the province’s vast mineral wealth—including tin (cassiterite), tantalum (coltan), tungsten (wolframite), and gold, which are critical for global electronics and industrial production.

The U.S. has warned of possible sanctions against Rwandan and Congolese officials ahead of a summit meant to address the escalating conflict in eastern Congo, according to a diplomatic note seen by Reuters on Friday.