Russia and Ukraine have repeatedly accused each other of firing at the Zaporizhzhia facility, which pro-Moscow forces took over soon after the Feb. 24 invasion. The U.N. has called for the area to be demilitarized.
"I'm continuing to consult very actively and intensively with all parties," IAEA chief Rafael Grossi said in a statement.
"The mission (to Zaporizhzhia) is expected to take place within the next few days if ongoing negotiations succeed."
Russia's U.N. ambassador Vassily Nebenzia on Tuesday told the U.N. Security Council that his country is expecting the IAEA's visit to Zaporizhzhya to take place "in the very near future" and Russia stands "ready to extend maximum support possible to resolve all organizational issues."
Ukraine's Zaporizhzhia nuclear power plant, Europe's largest, was overrun by Russian troops in March. It remains close to the frontlines and has come under repeated shelling in recent weeks, raising fears of a nuclear disaster.