British Prime Minister David Cameron on Monday described as “hugely concerning” the current tensions between Iran and Saudi Arabia.
Cameron also condemned the execution of the top Shia cleric Sheikh Nimr al-Nimr by the Saudi government.
Sheikh Nimr al-Nimr was put to death on Saturday with 46 other people, setting off a chain of protests in several Muslim countries including Iran, Iraq, Bahrain and Saudi Arabia, itself.
"It is hugely concerning because of course we want to see stability in the Middle East... not least because that will be absolutely essential for solving the crisis in Syria which is the source of so many of these problems," Cameron said on a visit to east London.
"We condemn and do not support the death penalty in any circumstances and that includes Saudi Arabia... we always make representations on the death penalty and the foreign office ministers made it very clear on this occasion."
Saudi Arabia is Britain's most important trade partner in the Middle East and was its biggest market for arms exports in 2014, AFP reported.
The British government, itself, is facing criticisms at home over its relations with Saudi Arabia.
The Green Party and the Liberal Democrats have specifically called on the government to clarify its role in Saudi Arabia's membership in the UN Human Rights Council (UNHRC). They say the kingdom’s mass executions have cast doubt on whether Riyadh should be a member of the UNHRC.
The two party leaders want a full response to last year's leak of diplomatic cables which revealed a secret vote-trading deal between Britain and Saudi Arabia to make sure both got a place on the UN Human Rights Council.
They have also called on Cameron to take measure to suspend exports of arms to Saudi Arabia.