Saudi 'might not' last two weeks without US military backing: Trump

President Donald Trump said Saudi Arabia's king "might not be there for two weeks" without US military support, as he sought to pressure his ally to boost oil production and bring down the price of brent crude ahead of mid-term elections.

Speaking at a campaign rally Tuesday night in Mississippi, Trump said: "I love the king, King Salman, but I said, 'King, we're protecting you. You might not be there for two weeks without us. You have to pay for your military, you have to pay'".

Trump didn't elaborate on when he spoke to the king. Trump and King Salman last shared a reported telephone call on Saturday.

Trump's Tuesday remarks echo his comments from a separate campaign rally on Sunday, in West Virginia, when the US president complained of "subsidising" the Saudi military just after saying "he loved" the kingdom.

Washington has a massive military presence in the Arabian Gulf - where oil supplies are vital for US industry - costing American taxpayers tens of billions of dollars each year.

Trump has characterised this as a form of "subsidy". 

Trump has also long complained that allies, particularly European members of NATO, do not pay enough for their own defence.

Benchmark Brent crude oil is near $85 a barrel - a four-year high - and analysts say it could reach $100. US gasoline prices are up ahead of November midterm elections.

However, experts say Saudi Arabia and OPEC are unable to curb the rise in oil prices unless they can fill the shortfall of Iran's falling exports, which have tumbled in the wake of US sanctions.

Iran's oil exports are expected to drop by a million barrels a day in the coming months as sanctions take their bite on the country.

Trump pulled out of the landmark 2015 nuclear deal in May and a second set of US sanctions targeting Iran's oil sector take effect on 4 November. Administration officials have expressed their desire to bring Iranian oil exports to zero.

They have also threatened secondary sanctions against businesses that buy Iranian oil. 

Saudi Arabia has been criticised by human rights groups following Crown Prince Mohammed bin Salman's campaign to suppress dissent in the country.

Trump has been largely silent on the purge of human rights campaigners in the kingdom, but has come under pressure to speak out against Riyadh's mass arrest of pro-democracy and women's rights activists.

This campaign to silence dissent took a new turn this week, when it appeared that a renowned Saudi journalist - who has been critical of the regime - had been "kidnapped" by authorities after visiting his country's consulate in Turkey.

Turkish police opened an investigation into the disappearance of Jamal Khashoggi on Tuesday, who vanished after visiting the Saudi diplomatic mission in Istanbul for routine paperwork this week. 

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