The Ontario government has put 'a gun to the head' of First Nations leaders trying to negotiate a fair deal in the Ring of Fire mining area in the James Bay lowlands, Neskantaga Chief Peter Moonias says.

His comments came within hours of Noront Resources announcement on Monday that it had struck a deal to buy Cliffs Natural Resources assets in the area.

Chiefs were informed of the deal at the same time as being told that the province has set an April 1 deadline for a decision on the next step in Noront's environmental assessment for a proposed nickel mine in the Ring of Fire, Moonias said.

"There's a hidden agenda," he said. "We are being targeted with a gun to our head. We have no more opportunity to study the process."

The deadline doesn't allow enough time for community members in the nine First Nations closest to the Ring of Fire mineral deposits to be informed, Moonias said.

The Matawa First Nations are engaged in a negotiation process about the mining project under a framework agreement with Ontario. Moonias said the sudden announcement of the tight timeline left him disillusioned about the talks.

"What will it take to fix it? It will take chiefs to stand up and say that's it," Moonias said. "Because the government is going to continuously do that to us, to not allow us to do our own process in our community."

Noront originally submitted its terms of reference for the environmental assessment for its proposed Eagle's Nest mine in 2012. The Ontario government website says it continues to be under review. 

When Noront's deal with Cliffs closes, the company said it will own approximately 65 per cent of all Ring of Fire claims.