In Britain visiting US President Barack Obama has addressed the UK Parliament, and held a news conference with Prime Minister David Cameron.

US President Barack Obama listens to Britain's Prime Minister David Cameron at a joint press conference at the Lancaster House in London.

They reaffirmed that their Trans-Atlantic Alliance will remain strong and indispensable. The two leaders also discussed Israeli-Palestinian relations, as well as the Libya situation.

UK Prime Minister David Cameron and US President Barack Obama have, once again, underlined the importance of bilateral relations, referring to their ties as special and essential.

Cameron spoke about the shared history between the two countries, as well as their mutual business and scientific ventures.

Cameron said, "That is what makes this relationship special. But what makes it essential, is that it's not just about history or sentiment. It is a living, working, partnership. It is essential to our security, and it's essential for our prosperity."

Obama was equally warm about the relationship.

In the wide-ranging session, the two leaders reaffirmed their joint resolve on Libya. The US President then said he believes a two-state Israeli-Palestinian solution is achievable, but urged both sides to return to the negotiating table.

Obama also reiterated their commitment to supporting the desire for democracy across the Middle East.

Obama said, "As historic change unfolds across the Middle East and North Africa, we agree that the pursuit of self-determination must be driven by the peoples of the region, and not imposed from the outside. But we are both committed to doing everything that we can, to support peoples who reach for democracy, and leaders who implement democratic reform."

Obama's speech to Parliament, and the ensuing news conference, came on the third day of his four-country, six-day European tour. The American leader is now scheduled to head to France for an economic summit, and will wrap up his trip in Poland.