Their joint statement followed Israeli strikes that have killed at least 16 Palestinians in the Gaza Strip since Tuesday, according to medics; Israel says it is targeting Hamas militants.
US envoy Jared Kushner wrapped up a regional visit on Monday amid attempts to advance US President Donald Trump's plan to end the war.
"The intensification of Israeli attacks undermines regional and international efforts at a critical juncture, as intensive efforts are under way to implement the Comprehensive Plan to End the Gaza Conflict," they said.
The international community and Trump's Board of Peace, which is overseeing the ceasefire, must take the necessary steps to ensure compliance and prevent further escalation, they added.
A proposed road map envisaged Hamas giving up its weapons in phases as Israeli forces withdrew from the enclave and halted military operations.
Israeli Prime Minister Benjamin Netanyahu rejected that sequencing, insisting that Hamas must fully disarm before an Israeli withdrawal.
Hamas has demanded that Israel adhere to the ceasefire and withdraw its forces from the Gaza Strip.
Hamas has also disputed the sequencing of how Trump's plan should be implemented.
At least 1,283 Palestinians have been killed in the territory since the ceasefire took effect last October, according to Gazan health officials, while the Israeli military says four Israeli soldiers have been killed.
