Israel's military is poised to evacuate Palestinian civilians from Rafah and assault Hamas hold-outs there, a senior Israeli defence official said on Wednesday, despite international warnings of a humanitarian catastrophe.
Washington has said it could not support a Rafah operation without an appropriate and credible humanitarian plan.
"They've assured us that they won't go into Rafah until we've had a chance to really share our perspectives and our concerns with them," Kirby told ABC.
U.S. Secretary of State Antony Blinken is due to visit the region next week and Kirby said he would continue pressing for a temporary ceasefire that Washington wants to last for at least six weeks.
A Hamas delegation will visit Cairo on Monday for talks aimed at securing a ceasefire, a Hamas official told Reuters.
"What we're hoping is that after six weeks of a temporary ceasefire, we can maybe get something more enduring in place," said Kirby, who also noted that the number of aid trucks into the north of Gaza was starting to increase.
"The Israelis have started to meet the commitments that (U.S.) President (Joe) Biden asked them to meet," he said.
Earlier this month Biden told Prime Minister Benjamin Netanyahu to protect Palestinian civilians and foreign aid workers in Gaza or Washington could rein in support for Israel in its war against Hamas.