The Philippines has seen the price of fuel hit historic highs since the US-Israeli war with Iran forced the partial closure of the Strait of Hormuz, with President Ferdinand Marcos most recently saying stocks could last until June 30.

AFP reported last week that a tanker filled with Russian crude oil had arrived at the harbour servicing refinery operator Petron Corp, a purchase unthinkable before longtime treaty ally the United States eased sanctions tied to Moscow's war in Ukraine.

In a report to the Philippine stock exchange released Monday, Petron said it had agreed to purchase Russian crude after seeing at least four million barrels in shipments cancelled since the start of the Middle East war.

"The purchases were undertaken strictly out of extreme necessity as an extraordinary emergency measure in response to unprecedented geopolitical and supply-chain disruptions and only after exhausting all commercially and operationally viable alternatives," the report reads.

"A refinery shutdown for failure to secure crude would lead to serious nationwide fuel shortages and sharp price spikes," said the company, whose refinery accounts for about 30 percent of the country's fuel needs.

Since the war began, the cost of diesel and gasoline has skyrocketed, driving protests by groups representing the country's jeepney drivers and others.

Prices were set to tick up again on Tuesday.

The United States earlier this month eased some restrictions on sales of Russian crude, allowing countries to purchase oil that was already at sea until April 11.

The Philippines' Department of Energy last week announced the arrival of 142,000 barrels of government-procured diesel, part of its target of "up to two million barrels of additional supply for the country".

Energy secretary Sharon Garin told AFP that shipment had come from Japan.