British Prime Minister David Cameron arrived in Saudi Arabia on Friday for talks with King Abdullah, state media reported, as tensions soar between the West and Tehran.
Cameron's first visit to Saudi comes as Western governments, including Britain, have moved to step up sanctions over Iran's nuclear programme, threatening an embargo on vital oil exports that has drawn an angry response from Tehran.
Britain has been seeking to strengthen ties with oil-rich Saudi Arabia and boost exports to its largest Middle East trading partner.
Annual bilateral trade is worth 15 billion pounds ($23 billion), while Saudi investments in Britain amount to more than 62 billion pounds.
As well as discussing closer commercial ties, the talks between the British premier and the Saudi monarch will focus on "regional and international issues of common interest," the official SPA news agency reported.
Energy security is also likely to be high on the agenda, with Iran having threatened to shut the strategic Strait of Hormuz - a chokepoint for a fifth of the world's oil - if it is attacked or if heavy sanctions are imposed.