Obama talks to focus on Libya, Afghanistan

As the focus of his state visit shifts to politics, Obama will also address MPs and peers in Westminster Hall.

On Tuesday, Obama praised the solidarity the UK had shown the US.

He was speaking at a banquet, in honour of his three-day visit, hosted by the Queen at Buckingham Palace.

He and wife Michelle also laid a wreath on the Tomb of the Unknown Warrior in Westminster Abbey and met the newly married Duke and Duchess of Cambridge.

At the evening banquet, the Queen gave a toast to what she called the "tried, tested and, yes, special relationship between our two nations".

She said: "I firmly believe that the strength of our links and many shared interests will continue to ensure that, when the US and the UK stand together, our people and other people of goodwill around the world will be more secure and can become more prosperous."

Obama said the Queen was "a living witness to the power of our alliance and the chief source of its resilience".

He thanked the UK for its solidarity since the 9/11 attacks 10 years ago and in tackling the security threats that have followed, and also paid tribute to the UK's military forces for "standing shoulder to shoulder with the US for decades".

The Nato operation in Libya and ongoing tensions in the Middle East and north Africa are expected to be high on the agenda when Cameron and Obama meet in the morning in Downing Street.

Clegg will also attend the talks, where the state of the global economy, counter-terrorism and the conflict in Afghanistan are also likely to feature.

After the meeting, the two men are expected to hold a joint press conference and drop in on the barbecue before heading to Buckingham Palace for a private lunch.

Later in the day, Obama will give a speech on US foreign policy at Westminster Hall, an honour usually reserved for British monarchs.

The hall has seen speeches from a number of heads of state - most recently Pope Benedict XVI in 2010 - but Obama will be the first US president to give an address there to both Houses of Parliament.

While the president gives his speech, his wife Michelle will travel to Oxford University where she will host an open day for pupils from the Elizabeth Garrett Anderson School in north London.

The visit is designed to encourage them to apply for further education.

On Thursday, the president and Cameron will both fly to France for the G8 summit of leading industrialised nations in Deauville.

During his speech at Westminster Hall, Obama is expected to say that the US has no closer ally in the world than the UK.

In a joint article in the Times on Tuesday, he and Cameron described the relationship between the two countries as "not just special" but "essential - for us and the world".

Obama also met Miliband at Buckingham Palace on Tuesday.

The two men reportedly discussed the challenges facing "progressive politics" on both sides of the Atlantic, as well as climate change and the situations in Afghanistan, Pakistan and Libya.