PARIS (Reuters) -Europe's Airbus posted stronger-than-expected revenues and core profit for the first quarter and reaffirmed targets for the year, while stressing it was too early to quantify the impact of tariffs.

The world's largest planemaker said its widely watched adjusted operating income rose 8% to 624 million euros ($707 million) and revenues gained 6% to 13.54 billion euros in the quarter, led by defence which smoothed the impact of lower jetliner deliveries.

Analysts had on average expected adjusted or underlying operating profit of 602 million euros on revenues of 12.95 billion, according to consensus data compiled by the company. Airbus also burned significantly less cash than expected.

Boeing's European rival continued to project 820 aircraft deliveries for 2025, up from 766 last year, but cautioned these would once again be backloaded towards the latter part of the year as it faces supply chain problems.

The company, which finalised an agreement on Monday to take over some factories of ailing Spirit AeroSystems, said the U.S. aerostructure supplier's difficulties were continuing to put pressure on the ramp-up of the Airbus A320 and A350 jets.

It held output forecasts unchanged, however, and stuck with 2025 financial forecasts that include 7.0 billion euros of adjusted operating profit - a measure routinely used by Airbus to exclude gains and losses related to restructuring, currency and certain other factors.

The 2025 forecasts include the impact of absorbing part of Spirit but not the uncertainty surrounding a growing tariff war.

"We are closely monitoring and assessing the situation, but it is too early to quantify the (tariff) impact today," CEO Guillaume Faury said in a statement.

Airbus said it was in "constructive" talks with purchasing nations for the A400M military airlifter, while studying the impact of the current state of orders on manufacturing plans.

The A400M has been hit by delays, partial cancellations by European launch nations and slow exports, with the order pipeline expected to run out in 2028. But industry sources have said higher European arms spending could revive interest from buyers that have curbed deliveries, such as France and Spain.

Airbus also announced new charges of 105 million euros related to the ongoing restructuring of its Defence and Space division.

($1 = 0.8821 euros)

(Reporting by Tim Hepher, Editing by GV De Clercq)