Prime Minister Binyamin Netanyahu headed to Washington this morning (Sunday), ahead of his address to Congress later this week.

Speaking to reporters prior to leaving for the US, Netanyahu described his upcoming speech to Congress - which has been the source of considerable tension with the White House - as "a critical mission, even a historic one."

"I feel like an emissary of all of Israel, even those who do not agree with me," he said, adding that "I sense a deep angst for the fate of Israel; I will do everything to assure our future."

Last night, Netanyahu paid a visit to the Kotel (Western Wall) in Jerusalem, where he also related to his upcoming journey.

"On the eve of my flight to the United States, I wanted to come here, to the Western Wall," he said to reporters at the Wall, playing down perceptions that his speech was a slight towards US President Obama.

"I want to take this opportunity to say that I respect the President of the United States, Barack Obama. I believe in the power of the relationship between Israel and the US, and their ability to overpower the differences – those that we have had and those that, one imagines, are still to come."

However, he emphasized that his decision to address Congress despite the White House's objections were the result of his fears over the existential threat posed to Israel by a "bad" deal with Iran over its nuclear program.

"As the prime minister of Israel it is my duty to safeguard the security of Israel, and that is why we strenuously oppose the deal that is forming between Iran and the powers, which can endanger our very existence.

"In the face of an agreement like this, we must unite and explain the dangers that stem from such an agreement, to Israel, to the region, and to the entire world."

At the same time, in a video posted by Netanyahu on Facebook the PM also noted how Israel had in the past ignored US objections to preserve its future - most notably in preemptively striking the amassed Arab armies in the 1967 Six Day War despite the opposition of the US. 

In the text accompanying the video, Netanyahu says: "In matters that endanger our very existence as a nation and as a state, the prime minister must make a stand to defend the security of Israel's citizens. Even if it entails differences with the White House – that we will know how to overcome, as we did in the past.”