Former government officials suggested Tuesday the Trump administration could reach for either the retired W84 warhead or the workhorse W80 warhead if it wants a nuclear-tipped option in the post-intermediate-range-nuclear-forces treaty era.

Trump announced Saturday the U.S. would cease complying with the 1987 intermediate range nuclear forces (INF) treaty, which forbids the U.S. and Russia from testing or deploying ground-based missiles — conventional or nuclear — designed to operate between 500 kilometers and 5,500 kilometers, or about 310 miles and 3,100 miles.

While Trump signaled the U.S. would start developing missiles that could be operated in the treaty-prohibited range, he did not say that Washington would proceed straight to a nuclear option. The Pentagon is already studying a conventionally armed INF-range missile under a directive Congress wrote into the 2018 National Defense Authorization Act.

If Trump does decide a ground-launched nuclear option is warranted, the 1980s-vintage W84 that used to tip ground launched cruise missiles prohibited by the INF is an option, consultant and former George W. Bush National Security Council hand Frank Miller said Monday in a conference call for the media hosted by the Washington-based Atlantic Council.

Another option is the W80, a slightly older weapon used on current air-launched cruise missiles and planned for use on future air-launched cruise missiles, Miller said.

If either warhead were re-purposed for a new INF-range weapon, “there’d be a degree of, at a minimum, refurbishment, etc. that would be required” by the Department of Energy, Jim Miller, former under secretary of defense for policy in the Barack Obama administration from 2012 to 2014, said on the Atlantic Council conference call. The Millers are not related.

Trump said chief his national security adviser, John Bolton, would discuss the U.S. plan to abandon INF this week in a private meeting with Russian president Vladimir Putin. Bolton arrived in Moscow Monday, state-controlled Russian information services reported.

Following Trump’s announcement, the Kremlin said it would continue to abide by the INF. U.S. politicians on both sides of the aisle, as well as current and former government officials on both sides of the aisle, say Russia has been violating the INF for a decade or so by designing and testing a missile capable of operating in the treaty-prohibited range. Moscow denies this.

After Trump’s bombshell announcement over the weekend, GOP Sens. Bob Corker (R-Tenn.) and Rand Paul (R-Ky.) rallied in support of INF. 

In a gaggle with reporters Monday, Army Col. Robert Manning, director of Pentagon press operations, said all future announcements about the INF will come out of the White House.

Meanwhile, the Trump administration’s 2018 Nuclear Posture Review from February had already asked the Defense Department to study a new nuclear-armed Sea Launched Cruise Missile. Unlike land-based missiles, sea-based options are not barred under the INF.

Hans Kristensen, director of the Nuclear Information Project at the Washington-based Federation of American Scientists, told Defense Daily the Trump administration was “probably more likely to use the W80″ than the W84 on a future Sea Launched Cruise Missile. The W80 once tipped the Tomahawk sea-launched cruise missile — the TLAM-N — scrapped earlier this decade by the Obama administration.

The W84, which Kristensen called “a modern warhead with some of the best safety and use-control features” in the arsenal, has been passed over for post-Cold War missions before.

When the Air Force and the Department of Energy were weighing options for the nuclear-armed Long Range Standoff Weapon — an air-launched cruise missile slated to enter service in the late 2020s — are developing, the agencies picked the W80 over the W84.

Lockheed Martin [LMT] and Raytheon [RTN] are maturing designs for the new air-launched LRSO cruise missile under four-and-a-half-year Pentagon contracts awarded in 2017 and worth about $900 million each.

Vivienne Machi contributed to this story from the Pentagon.