Weapons spending would climb to $15.6 billion to help modernize the nuclear stockpile — from extending the life of existing warheads to modifying a land-based intercontinental ballistic warhead to equipping submarines with the new W93 warhead, Energy Department officials said during a conference call with reporters.

“The president has chosen to put the U.S. back into the nuclear game,” Energy Secretary Dan Brouillette said.

Anti-nuclear watchdogs denounced the proposal to increase weapons spending.

“Taxpayers in 2020 should not be forced to pay for a ticket back to nuclear weapons policies of the 1980s,” John Tierney, executive director of the Center for Arms Control and Non-Proliferation, said in a statement.

Pit production funding wasn’t included in the overview. Energy Department officials said a full budget proposal would become available in the coming weeks.

About $2 billion would be earmarked for activities to foster nonproliferation, an increase of 4.5 percent, or $87 million, from this year’s level, the agency said in a news release.

Tierney said he was “greatly concerned” the funding for broader efforts of diplomacy and international affairs will be cut while Trump’s proposed $740 billion defense budget beefs up weapons spending.

“Globally, Trump’s nuclear weapons budget is fueling a new nuclear arms weapons race, particularly with a new plan for a new nuclear warhead,” said Jay Coghlan, executive director of New Mexico Nuclear Watch. “It solidifies Los Alamos lab’s future as a nuclear bomb plant, especially while nonproliferation, renewable energy and cleanup programs are held flat or cut.”

But Lisa Gordon-Hagerty, who heads the National Nuclear Security Administration, said the stepped-up weapons funding is necessary to modernize the nuclear stockpile and infrastructure after “decades of neglect.”

The budget request, she said, “reflects President Trump’s strong commitment to ensuring the nation has a safe, secure and effective nuclear deterrent for many decades to come.”

The Trump administration and some senators have pushed for Los Alamos lab and Savannah River Site to produce a combined 80 nuclear cores a year by 2030 to arm a future generation of warheads, such as the new, land-based W87-1 for intercontinental ballistic missiles.

The pits might also be used for the new W93 warhead being developed for Trident II intercontinental missiles. They would be launched from submarines and could travel more than 3,000 miles.

There has been talk of the Navy developing this new warhead for subs, but this is the first official announcement that it would be deployed. The news comes shortly after the Defense Department’s recent controversial move to put “low-yield” nuclear weapons, known as W76-2s, on submarines.

Proponents say the low-yield warheads, whose six-kiloton blast is a fraction of the warheads traditionally carried on subs, will allow the U.S. a tactical option other than all-out nuclear war. It also will discourage Russia from launching its low-yield weapons if it knows the U.S. can exchange tit for tat, they say.

Critics contend this is a dangerous game: If the U.S. fired a low-yield warhead, an adversary like Russia would not know it’s not a full-powered one and could strike back with its full nuclear force.

“First public confirmation of ‘W93’ as proposed new Navy nuclear warhead,” tweeted Stephen Young, an analyst with the Union of Concerned Scientists. “Entirely unclear WHY Navy needs a new warhead. W76-1 upgrade was just completed. NNSA seems to want to build new things. EXPENSIVE new things.”

New warheads don’t justify the weapons budget swelling to the point that the Energy Department has no clue how it will spend all the money, said Greg Mello, executive director of the Los Alamos Study Group.

The agency has yet to come up with a coherent plan on how to bring the lab’s old plutonium plant up to modern safety standards, Mello said.

“This is the largest proposed weapons design and production since the 1950s,” Mello said. “There are a lot of unanswered questions.”