Any impression of Syria getting away with its use of such arms would be taken as encouragement by Iran, which Israel and the West accuse of seeking to develop a nuclear arsenal, he said.
"Now it has to be ensured that the Syrian regime dismantles its chemical weapons and the world must make sure that those who use weapons of mass destruction will pay a price," Netanyahu said in remarks broadcast on army radio.
He did not elaborate, but earlier President Shimon Peres warned that Washington would take military action against Syria should it fail to destroy its chemical stockpile in line with a Russian proposal.
"If Syria is honest and will take real steps to remove and destroy the chemical weapons in its territory, the US will not attack," Peres said in a statement.
More From This Section
But "if there will be a crack in Syria's integrity, I have no doubt that the US will act militarily," he warned.
But he said it was too early to say if the Russian plan would succeed.
Syria demands the return of the Golan Heights which Israel, the Middle East's sole if undeclared nuclear power, seized in the 1967 Six-Day War and later annexed.