The appeal is in a joint statement signed by US President Joe Biden, Egyptian President Abdel Fattah-el Sisi, and Qatar's Emir Tamim bin Hamad Al Thani.
"There is no more time to waste or excuses from any party for further delays", they write.
According to the statement, a framework for the agreement has already been completed, and all that remains is the details of how it will be implemented.
High-ranking American diplomats have said in recent days that they are close to a solution that would include a ceasefire and the release of those still being held hostage.
We really believe we are in the final phase of an agreement on a framework, said Matthew Miller, spokesperson for the US Department of State, on Wednesday.
According to the proposal, the negotiations will be held in Doha or Cairo.
Israel's Prime Minister Benjamin Netanyahu announces that Israel will participate.
"Israel will on August 15 send a delegation of negotiators to the agreed-upon location to finalize the details of an agreement", Netanyahu's staff writes in a statement.
Hamas has not yet stated whether they will participate or not.
