Donald Trump says there will be "hell to pay" if Hamas does not disarm soon, following a meeting with Israeli Prime Minister Benjamin Netanyahu.
The US president has been hosting Mr Netanyahu at his residence in Florida for talks on Gaza and several other issues.
Mr Trump described the meeting on Monday, local time, as very productive and said Israel had lived up to a plan to end the war in Gaza.
He reiterated his call for Hamas to put down its weapons and said it would be given a short amount of time to do so.
"If they don't disarm, and they agreed to, then there'll be hell to pay for them, and we don't want that," Mr Trump told reporters.
Mr Trump said he and Mr Netanyahu had "come to a lot of conclusions" during the meeting and that they "agree on most of the things".
However, Mr Trump said: "I wouldn't say we agree on the issue of the West Bank 100 per cent, but we'll come to a conclusion on the West Bank."
Mr Trump would not be drawn on what the disagreement was regarding the Israeli-occupied territory, but said Mr Netanyahu would "do the right thing".
Following the meeting, the Pentagon announced it had awarded an $US8.6 billion ($12 billion) contract to Boeing for F-15 fighter jets for Israel.
Speaking ahead of the meeting, Mr Trump said he was eager to get to the second phase of the Gaza ceasefire deal, with its first phase beginning in October.
If successful, the second phase would see the rebuilding of a demilitarised Gaza under international supervision by a group chaired by Mr Trump and known as the Board of Peace.
The Palestinians would form a "technocratic, apolitical" committee to run daily affairs in Gaza, under the Board of Peace supervision.
After the meeting with Mr Trump, Mr Netanyahu did not rule out the Palestinian Authority having a role in governing Gaza in the future, should they undergo meaningful reforms.
Mr Netanyahu announced he had decided to award the Israel Prize, which is regarded as the state's highest honour, to Mr Trump.
Trump's warning to Iran
Speaking ahead of the meeting, Mr Trump warned Iran against reconstituting its nuclear program, saying the US would "knock the hell out of them" if it did.
Mr Trump has insisted that Tehran's nuclear capabilities were "completely and fully obliterated" by US strikes on key nuclear enrichment sites in June.
But Israeli officials have been quoted in local media expressing concern about Iran rebuilding its supply of long-range missiles capable of striking Israel.
"If they are, we're going to have to knock them down. We'll knock them down," Mr Trump told reporters.
"We'll knock the hell out of them. But hopefully that's not happening."
Iran has insisted that it is no longer enriching uranium at any site in the country, trying to signal to the West that it remains open to potential negotiations over its nuclear program.
The Iranian mission to the United Nations did not immediately respond to a request for comment on Mr Trump's warning.
Mr Trump criticised Iran anew for not making a deal to completely disarm its nuclear program ahead of the US and Israeli strikes earlier this year.
"They wish they made that deal," Mr Trump said.
ABC/wires
