By Jorge Otaola

BUENOS AIRES (Reuters) - Argentina's monthly inflation rate slowed down more than expected to come in at 13.2% in February, a boost for libertarian President Javier Milei who is pushing tough austerity to try to tame the world's fastest-rising prices.

The monthly rate, published on Tuesday, marks a deceleration from January, when prices rose 20.6%, and December, when they were up 25.5%. Analysts polled by Reuters had expected February's inflation rate to land at around 15%.

The 12-month rate through February, however, rose to 276.2%, below a poll forecast of 282.1%, but cementing Argentina's position as having the world's worst inflation, which is hammering people's spending power and driving up poverty.

Milei, battling an inherited crisis, has rolled out some tough measures to combat inflation, including painful cuts to state spending, targeting subsidies for things like utilities and transport, while looking to streamline welfare programs.

His government devalued the peso by over 50% in December, which caused prices to leap even faster, so he needs to demonstrate - and quickly - that his economic plan is bearing fruit to keep people onside and avoid unrest on the streets.

Milei's office on X said after the data was published that the slowdown was due to the government's work to impose "strong fiscal discipline."

However, the president has signaled that March could be "complicated," as signals in the economy have looked bleak, with tumbling sales, activity and production.

(Reporting by Hernan Nessi and Aida Pelaez-Fernandez; Editing by Kylie Madry)