German Chancellor Olaf Scholz said on Friday that "Hunger must not be used as a weapon."
"Everyone [at the G7 summit in Germany] agreed on the need to extend the Black Sea grain initiative," the unnamed U.S. official said.
The "G-7" group of nations is also "appreciative of the UN's efforts to convince Russia to extend" the grain deal.
Grain shipments from Ukraine resumed on Thursday after Russia returned to a deal allowing their safe passage following international pressure.
But Moscow said it had yet to decide whether to extend the grain deal beyond November 19 -- the renewal date written into the original agreement brokered by the UN and Turkey to stave off a global food emergency.
While pressing for the grain deal renewal, the G7's top diplomats on Thursday accused Russia of systematically destroying civilian infrastructure in Ukraine.
"They agreed that there needs to be some sort of a G7 coordinated mechanism to help Ukraine repair, defend and restore its energy and water infrastructure," the US official said.
Ukrainian Foreign Minister Dmytro Kuleba joined the meeting and "provided an update on the devastating attacks... on civilians, energy and water facilities," the official said.
G7 ministers on Thursday promised a winter aid package including generators, heaters, container housing, tents, beds and blankets.
German Foreign Minister Annalena Baerbock said Russia had "chosen a new method of warfare by trying to let people starve, die of thirst and freeze to death."