MEXICO CITY (AP) — Mexican President Andrés Manuel López Obrador said Sunday the army will run the Maya train project and several airports, and use any profits to finance military pensions.

The army is already overseeing construction on some parts of the controversial project, while private firms build the rest.

But López Obrador said Sunday that “so there won’t be the temptation to privatize” the $6.8 billion project, the army will operate it once built. The proceeds from that — and several airports, some of which the army is constructing — will be used to provide pensions for soldiers and sailors.

López Obrador has already given the army more tasks than any other recent Mexican president, with military personnel doing everything from building airports to transporting medicine and running tree nurseries. López Obrador said the army is among the most trustworthy and honest institutions in the country.

In July, López Obrador inaugurated the start of construction on the train, a pet project of his that would run some 950 miles (about 1,500 kilometers) in a rough loop around Yucatan.

The train is intended to connect Caribbean beach resorts to the peninsula’s interior, with largely Indigenous populations and ruin sites, in a bid to stimulate economic development around its 15 stations.

The government says it will cost as much as $6.8 billion, but others say it will be much more.

Critics have said the train will damage the environment and Maya communities along its path, and that proper environmental impact and feasibility studies have not been carried out.