LISBON (Reuters) - Portugal will build a new international airport in the municipality of Alcochete, across the River Tagus from Lisbon, Prime Minister Luis Montenegro announced on Tuesday after decades of back-and-forth over the location.

The new airport will be built at the site of a military airfield in Alcochete, about 40 km (25 miles) east of Lisbon, and should the ready by 2034. This location has been favoured by an independent technical commission, which had studied several possible sites.

The new airport will replace Lisbon's Humberto Delgado airport, just near the city centre, but the current airport will be expanded while the new airport is being built.

"The government sees having one single airport as a solution more suited to the country's strategic interests," Montenegro told a news conference.

Infrastructure Minister Miguel Pinto Luz said the project would cost up to 9 billion euros ($9.74 billion), adding it would be built using EU funds, public-private partnerships and airport tariffs and not through the state budget.

The government said it would initiate talks with airport operator ANA, owned by French construction firm Vinci. ANA already has a concession for a new airport in the Lisbon region.

To make it faster for passengers to get to Lisbon city centre from the Alcochete airport, the government said it would build a third bridge crossing the Tagus river. Pinto Luz said it was still not decided if the bridge would be just for trains or also for vehicles.

The announcement by the new centre-right minority government, which won a general election just two months ago, comes after several studies and decades of indecision.

The tourism industry has grown increasingly frustrated in the past few years as Lisbon's main airport is operating at full capacity.

Portugal is going through a tourism boom, which attracted record numbers of visitors. Foreigners staying in Portuguese hotels also made the first quarter of 2024 the best on record.

"I just hope this is a definitive decision and it won't be called into question by other governments, something we have unfortunately seen in recent years," said Francisco Calheiros, head of the Portuguese Tourism Confederation.

The government has also said it would build the long-delayed high-speed train connection between Lisbon and the Spanish capital by 2034. There are currently no direct rail links between Lisbon and Madrid.

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(Reporting by Patrícia Vicente Rua, Catarina Demony and Sergio Goncalves; Editing by Andrei Khalip and David Gregorio)