RYADH - US Secretary of State Antony Blinken discussed human rights with Saudi Arabia's Crown Prince Mohammed bin Salman (MbS) on Tuesday, during a trip aimed at boosting ties with a long-time ally that has forged closer relations with Washington's rivals.

Blinken's three-day visit to the oil-rich kingdom will also focus on efforts to end conflicts in Sudan and Yemen, the joint battle against the Islamic State group (IS) and the Arab world's relations with Israel.

His trip comes at a time of quickly shifting alliances in the Middle East, centred around a China-brokered rapprochement in March between regional heavyweights Saudi Arabia and Iran.

Another landmark change saw Syrian regime leader Bashar al-Assad invited back to the Arab League last month for the first time since the start of the 12-year civil war in which his government has been backed by Russia and Iran.

Damascus' readmission into the regional body, in which Saudi Arabia played a vital role, was met with intense criticism by the Syrian opposition.

Biden met Saudi Arabia's MbS on Tuesday and the two men had "an open, candid discussion that covered the full range of regional and bilateral issues", a US official said on condition of anonymity.

"The secretary raised human rights both generally and with regards to specific issues."

The meeting, which lasted about an hour and 40 minutes, touched on topics including Saudi Arabia's support for US evacuations from Sudan, the need for political dialogue in Yemen and the potential for the normalisation of relations with Israel.

Blinken landed in the Red Sea city of Jeddah on Tuesday evening and is expected to head to Riyadh Wednesday for a Gulf Cooperation Council meeting.

Energy prices

The visit is Blinken's first since the kingdom restored diplomatic ties with Iran, which the West considers a pariah over its contested nuclear activities and involvement in regional conflicts.

The United States offered cautious support for the deal that was sealed in China, the rising power making inroads in the Middle East.

US-Saudi relations, centred for decades on energy and defence, were badly strained by the 2018 murder of dissident journalist Jamal Khashoggi by Saudi agents.

Washington was also upset when Saudi Arabia, the world's biggest oil exporter, refused to help bring down skyrocketing energy prices after Russia's attack on Ukraine in February last year.

Rights activists including Abdullah Al-Qahtani, a US citizen whose father, Mohammad Al-Qahtani, was jailed for 10 years after founding a civil rights group in Saudi Arabia and who remains unaccounted for, urged Blinken to raise their concerns.

"He has to bring up my dad's situation. Is he alive? Is he being tortured? We don't know," Abdullah Al-Qahtani told a virtual news conference.

Prince Mohammed, 37, has steered an independent foreign policy course, also hosting Venezuelan President Nicolas Maduro on Monday.

Iran, the arch-foe of the United States and Israel for decades, reopened its embassy in Saudi Arabia on Tuesday following a seven-year hiatus.

Still, US-Saudi strategic relations remain close, especially on defence: Washington has long provided the Sunni Arab giant security protection from Shiite Iran, and Riyadh buys cutting-edge US weaponry.

Israel relations

US and Saudi diplomats have cooperated closely on efforts to broker a lasting ceasefire in Sudan's eight-week-old war, so far unsuccessfully, and Saudi help was crucial in evacuating thousands of foreigners from the war zone.

The two allies are also engaged in the ongoing battle against IS, the jihadist group that has lost all its territory in the Middle East but is increasingly active in parts of Africa.

They are also discussing efforts to end the conflict in Yemen, where a Saudi-led coalition has long provided military support to the government in a fight against Houthi rebels backed by Iran.

The United States also hopes that Saudi Arabia will eventually agree to normalise relations with Israel, which has already built ties with several other Arab nations under the controversial Abraham Accords brokered by the Donald Trump administration.

The normalisation of ties between Israel and the Arab states of Morocco, the UAE, Bahrain and Sudan was met with widespread condemnation by Palestinians. They described the move as a "stab in the back" for the Palestinian cause, as Israel continues to occupy the West Bank and east Jerusalem, as well as besiege the Gaza Strip.

On the eve of his Saudi trip, Blinken reiterated that "the United States has a real national security interest in promoting normalisation between Israel and Saudi Arabia".

He said Washington has "no illusions" that this can be done quickly or easily, but stressed that "we remain committed to working toward that outcome".

Despite normalisation rumours with Tel Aviv, Saudi Arabia has so far maintained that Israel must first recognise an independent Palestinian state.