BRUSSELS—The European Union will step up pressure on the Congolese government of President Joseph Kabila on Monday, with foreign ministers poised to impose sanctions against those allegedly responsible for stoking violence and fueling the country’s political crisis.

EU foreign ministers meeting in Luxembourg will discuss the turmoil in the Democratic Republic of Congo, including the postponement of next month’s elections and the antigovernment protests that followed in which dozens of people were killed.

In its announcement last month of the election delay, the DRC’s electoral commission said general elections wouldn’t take place until at least early 2018, a delay that risks further unrest and jeopardizes the fragile stability of the resource-rich nation.

Amid concerns that Mr. Kabila is trying to cling to power, Washington has already ratcheted up U.S. sanctions against the DRC, targeting two security officials it said were involved in recent violence.

According to the text of the statement the foreign ministers plan to issue Monday, which was completed earlier Friday, the EU will demand an independent inquiry into last month’s violence it blames mainly on government security forces. They will also press Mr. Kabila to move speedily to start a dialogue with the opposition and agree on a timetable for new presidential and parliamentary elections in 2017.