The United Nations envoy to Iraq has sparked a row after describing Israeli policy towards the Palestinians as "the big poison in the region".
Brahimi's comments have been described as "unacceptable"
Lakhdar Brahimi told French radio there was a link between Israeli actions and the recent upsurge of violence in Iraq.
He said that the handover of power in Iraq was being complicated by Israel's policies in the West Bank and Gaza.
UN Secretary General Kofi Annan's spokesman has reportedly described the comments as "unacceptable".
Mr Brahimi said his job was made more difficult by Israel's "violent and repressive security policy" and its "determination to occupy more and more Palestinian territory".
He added that people's perception in the region was of the "injustice" of Israeli policy compounded by the "thoughtless support" of the US.
The UN secretary general's spokesman, Fred Eckhard, told Israeli radio it was not acceptable for senior UN officials to make such comments about a member nation.
Arye Mekel, Israel's deputy ambassador to the UN, said his country was considering how to respond to the comments.
Mr Brahimi urged the US to start negotiating with Mr Annan about the UN's role after the 30 June handover of power.
"They have to start talking among themselves," he said. "It's difficult - there is a lot of hate in Iraq."
He also said the US had to learn how to live with a world in which it was the only super-power.
"There are lots of other people on this planet," he said. "They [the US] should make an effort to learn how to live with them."