David Cameron is to meet US vice president Joe Biden on Tuesday amid warnings from the Obama administration that it does not want Britain to leave the European Union.
Biden and his wife Jill arrived in the UK last night at the end of a short tour of Europe that also saw Obama's deputy visit Berlin and Paris.
Ahead of his meetings with the Prime Minister and the separate meeting he is due to have with Nick Clegg, Biden reiterated US concerns about the prospect of Britain withdrawing from the EU.
David Cameron is to meet with US Vice President Joe Biden
The issue has gained wider international interest amid growing Conservative demands for an in/out referendum, which Cameron last month finally promised to hold in 2017 if he wins the next general election.
He told the Times: "We value our essential relationship with the UK, as well as our relationship with the EU, which makes critical contributions to peace, prosperity, and security in Europe and around the world,"
"We believe the United Kingdom is stronger as a result of its membership. And we believe the EU is stronger with the UK's involvement. That's our view."
President Barack Obama has already told the Prime Minister in a phone call that the US "values a strong UK in a strong European Union".
Also likely to be on the agenda today are the security situation in north Africa, the continuing uprising in Syria, and Iran's nuclear programme.
While in Germany at the weekend, Biden said the US would be prepared to hold direct talks with Iran when its leadership demonstrated it was "serious".
He has also praised the French military action in Mali which Britain is supporting with the deployment of 200 military advisers to help train a West African intervention force.
The government has also offered 40 personnel to a European Union (EU) training mission to build up the fledgling Malian army.
Biden is expected to have a working lunch with Cameron in 10 Downing Street and attend the weekly National Security Council meeting.