(Adds details and background on refineries, energy minister's...

(Adds details and background on refineries, energy minister's comments)

SYDNEY, May 17 (Reuters) - Australia has reached a deal to keep its last two oil refineries open with up to A$2.3 billion ($1.79 billion) in support until 2030 to ensure the country's long-term fuel security, Prime Minister Scott Morrison said on Monday.

The package will help Ampol Ltd (ALD) and Viva Energy Group (VEA) keep their refineries open and save 1,250 jobs across the two plants, Morrison said.

"This is a key plank of our plan to secure Australia's recovery from the pandemic, and to prepare against any future crises," Morrison said in a statement.

The agreement follows on the government's offer last September seeking to keep the country's four refineries open, however, two of which have since announced closures.

The coronavirus-led collapse in fuel demand aggravated losses for the refiners, which were already reeling from tough competition from Asia's large refineries.

Australia last year had four refineries, which combined were smaller than the biggest plants in Asia.

Two of the four have since announced closures, with BP plc BP.L having shut its Kwinana plant in Western Australia in April and Exxon Mobil Corp XOM.N set to shut its Altona plant in Victoria later this year.

Combined, they had a capacity of around 464,000 barrels per day (bpd), but still small when compared with the 1.24 million bpd Jamnagar plant in India, Asia's biggest refinery.

Both Viva Energy and Ampol Ltd said on Monday they would continue operating their refineries until at least 2027 though they have an option to receive extended support out to mid-2030s.

The package assumes that both refineries are paid at the highest support rate over the entire nine years in COVID-19-like economic conditions, which is unlikely as the economy recovers.

Both refineries will be supported during difficult operating conditions and will not receive help during good times, Energy Minister Angus Taylor said, adding the government does not expect to spend the full support. ($1 = 1.2857 Australian dollars)