NEW YORK - Israel's main backers in the US are putting "extraordinary" public pressure on US President Barack Obama ahead of Prime Minister Benjamin Netanyahu's visit to Washington, demanding that Obama harden his stance with regards to the Iranian nuclear programme, the New York Times reported on Sunday.

As part of pressure being mounted from both the corridors of Congress and AIPAC, the powerful pro-Israeli lobbying group, the newspaper said Obama is being buffeted by demands that the United States be more aggressive toward Iran and more forthright in supporting Israel in its own confrontation with Tehran.

Obama will be meeting with President Shimon Peres on Sunday on the sidelines of the AIPAC conference which draws over 14,000 American Jews and other supporters of Israel.

Obama is set to speak after Peres as will the three leading Republican presidential candidates, who will appear via satellite from the campaign trail on the morning of Super Tuesday. Republicans have seized on Iran’s nuclear programme to accuse Obama of being weak in backing a staunch ally and in confronting a bitter foe.

Peres will tell Obama that the more credible the threat of attack against Iran, the more likely the possibility that there will be no need to use it, in which case sanctions will suffice.