US defence secretary: Iran's destabilisation efforts must be overcome to help Yemen

US Defence Secretary Jim Mattis said on Wednesday that Iran was playing a destabilising role in the Middle East but its influence would have to be overcome to bring about an end to the conflict in Yemen.

At least 10,000 people have been killed and more than 3 million displaced in the war in Yemen, now in its third year. Millions of people are also struggling to feed themselves.

"Everywhere you look if there is trouble in the region, you find Iran," Mattis told reporters in Riyadh after meeting senior Saudi officials.

"We will have to overcome Iran's efforts to destabilise yet another country and create another militia in their image of Lebanese Hezbollah, but the bottom line is we are on the right path for it," Mattis added.

Officials have said the United States is considering deepening its role in the conflict in Yemen by more directly assisting its Gulf allies, who are fighting Iranian-supported Houthi rebels there.

US officials speaking on condition of anonymity said the situation in Yemen came up in their meetings with Saudi officials, including with King Salman and Deputy Crown Prince and Minister of Defense Mohammed bin Salman.

Officials said US support for the Saudi-led coalition was discussed including what more assistance the United States could provide, including intelligence support.

The Iran-aligned Houthis control the Yemeni capital Sanaa and large swathes of territory. The United States backs the Saudi-led coalition which is trying to restore the government of President Abd-Rabbu Mansour Hadi, including through a devastating aerial bombing campaign.

Speaking earlier in the day before the start of a meeting with the deputy crown prince, Mattis said he hoped his trip could potentially open the door for US President Donald Trump to visit Saudi Arabia.