An emergency meeting of Arab and Islamic states is taking place in Qatar in response to Israel's air strike on Hamas leaders in Doha last week.
A draft resolution seen by the Reuters news agency condemns what it calls Israel's "hostile acts including genocide, ethnic cleansing, [and] starvation", which it says threatens "prospects of peace and coexistence". Israel has strongly denied such allegations.
It is not clear what practical decisions could be taken, as analysts say any kind of military response is out of the question.
Earlier, Qatari Prime Minister Mohammed bin Abdulrahman bin Jassim al-Thani urged the international community to stop applying "double standards" and to punish Israel.
On Sunday, US President Donald Trump said that "Qatar has been a very great ally. Israel and everybody else, we have to be careful. When we attack people we have to be careful."
Departing for Israel on Saturday, the US Secretary of State, Marco Rubio, said Trump "didn't like the way [the Qatar attack] went down".
After holding talks with Israeli Prime Minister Benjamin Netanyahu in Jerusalem the next day, Rubio said Hamas "needs to cease to exist as an armed element that can threaten the peace and security" in the Middle East.