The United States is very concerned that hostilities on the Israel-Lebanon border could escalate to a full-out war, a senior U.S. official said, saying that specific security arrangements are needed for the area and a ceasefire in Gaza is not enough.

The Iran-backed Hezbollah and Israel have been trading fire since the eruption of the Gaza war in October in steadily intensifying attacks that have fueled concern of a bigger confrontation.

“We have had consistent and urgent conversations at different times with Israel and Lebanon over the eight months, from the very beginning of this crisis … to keep this from developing into a full-out war that could have implications to beyond elsewhere in the region,” the official said.

“Returning to the status quo to Oct. 6 in Lebanon is not an acceptable or viable option.”

On Wednesday, Hezbollah fired the most rockets it has launched at Israel in a single day since cross-border hostilities broke out eight months ago, as part of its retaliation for an Israeli strike that killed a senior Hezbollah field commander.

Secretary of State Antony Blinken said in Doha on Wednesday that the best way to empower a diplomatic solution in the north of Israel is a resolution of the conflict in Gaza in the south.

“That will take a tremendous amount of pressure out of the system,” he said. “It will take away a justification that Hezbollah has claimed for the attacks its engaged in, and I think open a pathway to actually resolve this diplomatically.”

However, the U.S. official said more will be needed.

“It is not enough to just have a ceasefire…there has to be an agreement that allows Israelis to return to their homes in the north,” the official said.