The law, passed by Israel's parliament on Monday, will apply to Israelis convicted of murder whose attacks are aimed at "ending Israel's existence", meaning it would mete out the death penalty for Palestinians but not for Jewish Israelis who committed similar crimes, critics say.
Palestinian President Mahmoud Abbas has condemned the legislation as a breach of international law and a doomed bid to intimidate Palestinians.
Pakistan, Turkey, Egypt, Indonesia, Jordan, Qatar, Saudi Arabia and the United Arab Emirates said the law constituted a "dangerous escalation" and emphasised the "urgent need to refrain from measures" that risked further inflaming tensions on the ground, a joint statement released by Pakistan said on Thursday.
"They stressed the importance of ensuring accountability and called for strengthened international efforts to uphold stability and prevent further deterioration," it said.
The Taliban government in neighbouring Afghanistan also termed the legislation a "continuation of oppression", calling on "international organisations and influential countries to take immediate and practical steps to prevent such actions".
The law has drawn similar criticism from Western allies of Israel at a time when the country is already under scrutiny for increasing violence by Jewish settlers against Palestinians in the occupied West Bank.
The European Union and Germany had both expressed concern about the move, which was also opposed by Canada.
Supporters of the law argue the death penalty will deter Palestinians from carrying out deadly attacks against Israelis or attempting kidnappings with the aim of affecting swap deals for Palestinians jailed in Israeli prisons.
Israeli Prime Minister Benjamin Netanyahu, in an effort to head off backlash, asked for some elements of the legislation to be softened, Israeli media reported.
