Rice is the biggest food item in the country's consumer price index, which rose 6.7 percent in September from a year earlier, the fastest since February 2009 as low stockpiles caused domestic prices to rise sharply.

Duterte ordered the "unimpeded" imports of rice during a cabinet meeting on Monday, Harry Roque told a news briefing.

"There are no more restrictions as long as tariffs are paid," he said. "It's a free market now for rice."

That means scrapping a government cap on rice imports, in place for more than 20 years, a policy intended to protect domestic rice farmers. It also means ending a decades-long monopoly of rice purchases by the state's National Food Authority (NFA).

Lawmakers are currently working to replace the cap, or the so-called quantitative restriction, with a bill setting the tariff at 35 percent for supplies from Southeast Asia - the same as an existing regional trade agreement - and up to 180 percent for imports from elsewhere.

But Duterte's order suggests there is no need to wait for the new law as long as importers pay the tariffs.

Liberalising "the importation of rice was really the ultimate means by which to rein in inflation as far as food items are concerned," said Roque.

The spokesman said Duterte's order means there is no need now for the NFA to approve how much should be shipped in or accredit importers.

Despite his order, Duterte said there was enough domestic rice supply and that inflation was driven mainly by high oil prices. In a televised media briefing later on Tuesday, he said the government might suspend the imposition of excise tax on fuel products, without elaborating.

Agriculture Secretary Emmanuel Pinol, however, clarified that rice imports would not be totally liberalised because there are still other conditions, apart from tariff payments, that importers need to meet, such as sanitary requirements.

The Philippines is already on a rice buying spree this year, with import approvals by the NFA hitting 2.4 million tonnes, just below the record 2.45 million tonnes bought in 2010 when rising global food prices stoked shortage fears.

With more rice imports coming in, Pinol said local prices have begun to stabilise and that "things are going to get better" next month.

The Philippines' rice imports, which are much cheaper than locally grown varieties, usually come from Vietnam and Thailand, where production costs are much lower.

(Reporting by Enrico dela Cruz; Editing by Manolo Serapio Jr., Kenneth Maxwell and David Evans)