US President Barack Obama has hailed his country's ties with the UK as "indispensable" after welcoming British Prime Minister David Cameron to the White House.

Talks between the two are concerned with global issues, including Iran’s nuclear program, NATO’s war strategy in Afghanistan and the ongoing violence in Syria.

Both nations have been pressing Iran to provide clarification over its nuclear program although the US and the UK have both warned against a pre-emptive strike by Israel against Iranian nuclear facilities.

Cameron arrived in Washington on Tuesday as Obama was trying to limit the fallout from a shooting rampage by a rogue US soldier in Afghanistan.

It’s the latest incident putting a strain on Washington’s tense ties with Kabul with questions growing over US strategy in the country.