U.S. Secretary of State John Kerry delivers remarks on the United States foreign policy agenda 2016 at the National Defense University in Washington January 13, 2016.

U.S. Secretary of State John Kerry is to meet his Saudi counterpart Foreign Minister Adel al-Jubair in London on Thursday amid concerns over the dramatic breakdown in relations between his country and Iran.

On the eve of the trip, State Department spokesman Mark Toner said “they’ll discuss a range of issues, bilateral and global issues, including obviously Iran and the ongoing crisis in Syria.”

Washington and Riyadh have been close allies for decades but in recent months there has been mounting discord over the U.S. diplomatic outreach to Iran, which Saudi Arabia sees as a dangerous enemy.

Kerry now spends more time on the phone with Iranian Foreign Minister Mohammad Javad Zarif than he does with al-Jubair, most recently on Wednesday when he called Tehran five times to secure the release of captured U.S. sailors.

The State Department, nevertheless, insists that it retains close ties with Saudi Arabia and remains critical of what it calls Iran’s destabilizing role in the region, illegal ballistic missile program and sponsorship of extremist groups.

Committed

Kerry talks in London will be a new occasion for Kerry to try to reassure Jubair that Washington remains committed to their alliance, and to prepare the way for Syria peace talks later this month.

Saudi Arabia has taken a role in international efforts to broker an end to the Syrian civil war, coordinating a coalition of opposition and rebel groups that will send a joint negotiating team to Geneva on January 25.

For its part, Iran backs Bashar al-Assad’s regime and the Lebanese Hezbollah militia which supplies some of the most effective forces defending his rule and which Washington regards as a terrorist army.

Related articles across the web

• Syrian negotiator says opposition wants transition without Assad
• Snagging the Pipelines Cobweb: a checkmate for the US?
• Ahead of Syria Conference, US and Russia Soften Positions on Assad
• Russia open to Assad's ouster after Syria transition, diplomats
• The Syrian Civil War: Great News Out Of Syria - Syrian Army Holds Victory Parade In Homs After "Al Qaeda" Stronghold Is Cleared!
• These Are The Reasons Why Thousands Of Soldiers Have Deserted The Syrian Military
• End Times Prophecy Headlines: December 18, 2015
• Russia 'open to Al Assad's ouster after Syria transition'
• Putin just played Obama. Again.