A man watches a news report at a railway station in Seoul on September 15, 2015, on the confirmation from North Korea that the nuclear reactor seen as the country’s main source of weapons-grade plutonium had resumed normal operations.

A day after threatening long-range rocket launches, North Korea declared on Tuesday that it has upgraded and restarted all of its atomic fuel plants so it can produce more – and more sophisticated – nuclear weapons.

Neither announcement was entirely unexpected, and outside analysts see the back-to-back warnings as part of a general North Korean playbook of using claimed improvements in its nuclear and missile programs to push for talks with the United States that could eventually provide the impoverished country with concessions and eased sanctions.

But the threats could significantly deepen a standoff between North Korea and the U.S. and its allies because they strike at Washington’s fear that each North Korean rocket and nuclear test puts it another big step closer to its stated goal of an arsenal of nuclear-tipped long-range missiles that can hit the U.S. mainland.

North Korea has spent decades trying to develop just such a weapon, and while it is thought to have a small arsenal of atomic bombs and an impressive array of short- and medium-range missiles, it has yet to demonstrate that it can produce nuclear bombs small enough to place on a missile or can make reliable long-range missiles.

North Korea said on Tuesday in its state media that the plutonium and highly enriched uranium facilities at its main Nyongbyon nuclear complex have been “rearranged, changed or readjusted and they started normal operation,” and that its scientists had improved “the levels of nuclear weapons with various missions in quality and quantity.”

The world will “clearly see a series of satellites soaring into the sky at times and locations determined” by the Workers’ Party, an unidentified director at the North’s National Aerospace Development Administration director was quoted as saying by state media.

North Korea has said its satellite launches are peaceful and meant for weather observation, but the West considers them covers for banned tests of long-range missiles.

After several failures, North Korea put its first satellite into space with a long-range rocket launched in late 2012. The U.N. said it was a banned test of ballistic missile technology and imposed sanctions. Experts say that ballistic missiles and rockets used in satellite launches share similar bodies, engines and other technology.

An angry North Korea then conducted its third nuclear test in February 2013, inviting further international condemnation and sanctions. Later that year it threatened Seoul and Washington with nuclear strikes.

The Korean Peninsula remains in a technical state of war because the 1950-53 Korean War ended with an armistice, not a peace treaty. About 28,500 U.S. troops are stationed in South Korea as deterrence against potential aggression from North Korea.