Detailed "sensitive commercial conversations" are underway with utilities in Quebec, New Brunswick and Nova Scotia, he said.

"I'm very hopeful that those discussions will be fruitful and in the next few months we'll have an agreement in principle," LeBlanc told CBC News.

The Atlantic Loop would deliver hydroelectricity from Quebec and Labrador into Maritime provinces that currently rely mostly on fossil fuels for electricity.

Speaking after a university funding announcement, LeBlanc acknowledged a delay in reaching the agreement, but said that's not because of problems with the Muskrat Falls hydro project in Labrador. He said the Atlantic Loop discussions are focused on improving grid connections between Quebec and New Brunswick and New Brunswick and Nova Scotia.

"The particular conversations that we're having now involve a portion of the Loop that really are not related to Muskrat at this particular moment," he said.

Ottawa has set aside $20B for clean electricity projects

The most recent federal budget spelled out where Ottawa's financial contribution will come from.

The Canada Infrastructure Bank was allocated $20 billion to "support the building of major clean electricity and clean growth infrastructure projects" across Canada.

"These investments will position the Canada Infrastructure Bank as the government's primary financing tool for supporting clean electricity generation, transmission, and storage projects, including for major projects such as the Atlantic Loop," the 2023 budget document states.

Milestone 'slipped' by 3 months

LeBlanc admitted that reaching the milestone agreement in principle has "slipped by a quarter" but he's hoping the agreement will be in place by the end of June.

He attributed the delay to providing federal negotiator Serge Dupont with the detailed mandate to talk dollars. Dupont is a former senior federal civil servant.

Federal Infrastructure Minister Dominic LeBlanc, left, at a press conference with the CBC's Paul Withers on Tuesday. (CBC)

There was no indication a decision by Emera, the parent company of Nova Scotia Power, to pause the mega project has had an impact.

Emera announced it was stepping back last fall after Nova Scotia's Progressive Conservative government imposed a rate and spending cap on subsidiary NSP.

"I go by what Serge Dupont and officials from the Privy Council Office who are involved in these conversations tell me," said LeBlanc. 

"I'm not pessimistic at all. Serge Dupont reports to us that his conversations with Emera, as well as with the utilities in New Brunswick and in Quebec, are very encouraging."

In a statement to CBC News Tuesday, Nova Scotia Power confirmed it is engaged in discussions with both the federal and provincial governments and neighbouring utilities.

"As the operator of the province's energy grid, we have an important role to play in meeting ambitious climate goals at the federal and provincial level as Nova Scotia transitions to cleaner energy. The Atlantic Loop has the potential to be an important part of the solution for the region. Federal support is critical to reducing the cost impacts of the clean energy transition for customers," spokesperson Jackie Foster said.

Is completion by 2030 feasible?

Last week's federal budget defined the Atlantic Loop as "a series of interprovincial transmission lines that will provide clean electricity between Quebec, New Brunswick, and Nova Scotia."

It did not include the other half of the Loop: hydroelectricity generated from Muskrat Falls in Labrador, sent into Newfoundland and across the Cabot Strait into Nova Scotia.

The budget commits Ottawa to negotiations for a 2030 project delivery.

It is also the deadline to close plants that generate electricity by burning coal.

LeBlanc said he was hopeful that timeline can still be met.

"I'm every bit as optimistic as I was before that we can have this significant mega project online by 2030. But time is of the essence and we recognize on our side we can't cause any delays and we hope that the utilities and the provinces are as committed as we think they are to getting the right deal for Nova Scotians and for New Brunswickers and Atlantic Canadians," he said.