Republican presidential front-runner Donald Trump says he may cut off oil purchases from Arab allies such as Saudi Arabia unless their governments pay for US protection or provide troops to fight the Islamic State (IS).
The former Celebrity Apprentice host's comments were made to the New York Times in a lengthy foreign policy-focused interview, in which he also said he might rethink traditional US alliances should he become president.
Trump has threatened allies of the US that he may demand reimbursement for the military protection the superpower provides, even those with enormous oil resources such as Saudi Arabia.
"Without us, Saudi Arabia wouldn't exist for very long," says Trump.
"We're not being reimbursed for the kind of tremendous service that we're performing by protecting various countries. Now Saudi Arabia's one of them."
Trump's chief complaint about US' Arab allies is one which many in the Obama administration share -- that they often look to the United States to police the Middle East, without putting their own troops at risk.
"We defend everybody. When in doubt, come to the United States. We'll defend you. In some cases, free of charge," says Trump.
During his campaigning, Trump has promised to "cut off the head" of IS and "take their oil". In the interview, he begrudgingly acknowledged that this would require deploying ground troops.
He also said the US should've taken the now IS-controlled oil in Iraq during the occupation years following the 2003 invasion, and because it didn't, that oil should now be destroyed.
On the Israel/Palestine conflict, Trump said he supported a two-state solution, although insisted that the Palestinian authority must recognise Israel's right to exist as a Jewish state.
Trump also claimed that the alliance with Japan was "one-sided" and part of the US's "path of weakness".
He also emphasised the importance of 'unpredictability' for US presidents, as Nixon did before him, playing coy with his plans for spying on European allies and military strategy in the South China Sea.
Trump also named some of his military advisors in the interview.