Lawyer Alan Dershowitz has criticised Norway's Israel ambassador for "suggesting Hamas terrorism against Israel is more justified than the recent terrorist attack against Norway".
Svein Sevje told Israeli newspaper Maariv that Palestinians "are doing this because of a defined goal that is related to the Israeli occupation. There are elements of revenge against Israel and hatred of Israel. To this you can add the religious element to their actions.
"We Norwegians consider the occupation to be the cause of the terror against Israel. Those who believe this will not change their mind because of the attack in Oslo."
Mr Deshowitz said he "could not remember many other examples of so much nonsense compressed in so short an interview.
"I know of no reasonable person who has tried to justify the terrorist attacks against Norway.
"Yet there are many Norwegians who not only justify terrorist attacks against Israel, but praise them, support them, help finance them and legitimate them."
Mr Dershowitz has previously called Norway "the worst country in the world when it comes to its record on Israel and the Jews".
Mr Sevje had written to Maariv, claiming he "did not seek to convey any personal or governmental position regarding the motivation behind terror attacks against Israel, nor to compare terror attacks in Israel and Norway".