The city-state had planned to require departing flights to use the more expensive Sustainable Aviation Fuel (SAF) in their mix starting this year, and to collect a levy on tickets to finance that.

SAF -- a biofuel made from plant and animal materials like cooking oil and fat, which produces lower carbon emissions than traditional jet fuel -- is crucial to the airline industry's bid to cut carbon emissions.

Authorities previously said they would start charging the levy on tickets sold from April 1 for flights departing Singapore starting October 1.

But the Civil Aviation Authority of Singapore (CAAS) said in a statement on Wednesday that the levy will now be applied to tickets sold from October 1 for flights departing from January 1.

"The Civil Aviation Authority of Singapore will defer the implementation of the SAF levy, in view of the impact of the ongoing conflict in the Middle East on airlines and passengers," the regulator said.

CAAS director-general Han Kok Juan said that, while Singapore remains committed to cutting carbon emissions, "we are taking a pragmatic pause in view of the current situation."

CAAS said in a follow-up statement that with the deferment of the levy's implementation, the target to require one-percent SAF in the fuel mix will now apply from 2027.

"Our intent is still to raise the target to 3-5 percent by 2030, subject to global developments and the wider availability and adoption of SAF," the regulator added.

Oil prices have soared since the US-Israeli war against Iran disrupted tanker shipping through the Strait of Hormuz, sending shockwaves through the global economy.

"We will continue to work closely with our aviation industry partners and monitor global developments," Han said.