The United Nations, African Union, European Union and the International Organisation of the Francophonie "are increasingly concerned by the continuing impasse in the dialogue among the political stakeholders" in DRC, a joint statement said.
The talks aim to implement a power-sharing deal signed on New Year's Eve by the government and the opposition to end a political crisis over President Joseph Kabila's fate.
Kabila's second and final mandate ran out in December but elections did not take place.
Under the terms of the deal, Kabila would remain in office as president until the "end of 2017" but a transition council was to be established under the leadership of veteran opposition leader Etienne Tshisekedi.
In addition, a prime minister was to be named from the opposition ranks.
But Tshisekedi's death two weeks ago has complicated an already strained situation as politicians vie for the top spot.
"This situation has the potential to undermine the political goodwill that led to the signing of the 31 December agreement," the statement said.
They called on the stakeholders "to redouble, in good faith, their efforts towards a speedy conclusion of the ongoing talks."
The talks launched by the Roman Catholic church, were intended to ward off violence as Kabila's mandate ended on December 20 with no sign of him stepping down and no election in sight.
The four partner organisations said the agreement "is critical in upholding the legitimacy of the transitional institutions until elections."