Defending his speech in the US Congress on Tuesday, Israeli Prime Minister Benjamin Netanyahu insisted that he had presented a "practical alternative" to a planned US-led deal with Iran on Tehran's nuclear program.

He said "that though tougher restrictions would extend the breakout time, by years, that it would take Iran to reach a nuclear weapon if it decides to breach the agreement," according to a statement released by the prime minister's office on Wednesday.

Netanyahu received standing ovations from a Republican-dominated Congress on Tuesday, but his speech ruffled more than a few feathers in the White House, with both US President Barack Obama and Vice President Joe Biden refusing to attend the speech or meet him during his 48-hour trip to Washington.

Obama had dismissed Netanyahu's move as "theater" and said that "as far as I can tell, there was nothing new" and "no viable alternatives."

In defense of his speech, the Israeli prime minister also said his proposal would maintain restrictions until Tehran stops "its sponsorship of terrorism around the world, its aggression against its neighbors and its calls for Israel's destruction." He said he was "encouraged" by the response from both Republicans and Democrats.

Netanyahu had been invited to speak in Congress by the speaker of the House of Representatives, John Boehner, but Netanyahu is seen to have broken diplomatic protocol by not consulting the White House first.

The move came two weeks ahead of parliamentary elections in Israel and ahead of a June-30 deadline to reach an international, US-led final agreement with Tehran on its nuclear program.

Netanyahu's speech also coincided with a round of bilateral talks between the foreign ministers of Iran and the US in Geneva, Switzerland, which concluded on Wednesday.

The so-called P5+1 talks between Iran and the US, Russia, China the UK, France and Germany had led to an interim agreement in November 2013.

Iran insists its nuclear program is for peaceful purposes only, but there are widespread concerns that Tehran is attempting to establish itself as a nuclear weapons power.

ng/kms (AP, AFP, dpa)