The Organization of the Petroleum Exporting Countries (OPEC) will invite Russia, Oman, and Azerbaijan to June talks in Vienna, Venezuelan Oil Minister Eulogio Del Pino said Wednesday.

The three major oil producers, who are not OPEC member states, last met with members of the oil exporting cartel in Doha on April 17, in a failed bid to put through a February decision on capping oil production. The output freeze is expected to be brought up again at the talks in the Austrian capital.

“These countries have been intent on reaching a compromise. We have agreed to continue consultations, we will discuss agreements in Vienna in June. All these countries – Russia, Oman, Azerbaijan – will be invited and we hope to see them there,” Del Pino said.

The oil output freeze was first proposed at a Doha meeting of OPEC’s Saudi Arabia, Qatar, and Venezuela with Russia last February, in an attempt to reduce the supply glut that has pushed oil prices downward.

Oil prices have plunged more than 60 percent from their peak of $110 a barrel in June 2014 amid fears that the global oil production was outpacing the world’s demand.