The delay comes after Washington imposed new sanctions targeting Iran on Wednesday.
More than 50,000 police officers are deployed to the Turkish capital and public transport is shut down.
The BBC's analysis editor looks at what has been agreed in the much-anticipated agreement.
The sectarian violence involving Islamist factions, security forces and Druze gunmen is another sign of the fragile security situation.
The foreign minister of Oman credited the delay to 'logistical reasons', but the postponement comes amid new sanctions.
The airline has asked the Indian government for financial relief equivalent to its estimated losses.
Israeli forces are accused of targeting Palestinians collecting food for their families in Gaza.
The budget carrier said it might cancel 330 737 Max orders due to rising costs brought on by tariffs
Mohammed Khatib, who advocates for Palestinian prisoners, believes his detention was meant to silence him.
The US is pivoting back to fossil fuels, China is ramping up renewables, while Europe is trying to catch up.