Russian authorities have recommended residents of Nyonoksa leave their village while cleanup work is carried out nearby following a rocket engine accident that caused a spike in radiation last week, Interfax news agency reported citing local officials.

"We have received a notification … about the planned activities of the military authorities. In this regard, residents of Nyonoksa were asked to leave the territory of the village from Aug. 14," authorities in Severodvinsk were quoted as saying.

Russia's state weather service said radiation levels spiked in nearby Severodvinsk — a city of some 190,000 — by up to 16 times on Aug. 8 after what officials say was an explosion during a rocket engine test on a White Sea platform.

Nyonoksa hosts a navy facility that serves as a base for testing intercontinental ballistic missiles intended for nuclear submarines, and it is believed several hundred people are currently posted there.

The Kremlin boasted Tuesday it was winning the race to develop new cutting edge nuclear weapons despite the mysterious rocket accident in northern Russia last week, which killed at least five and injured three more.

In this video grab taken from footage provided by the Russian State Atomic Energy Corporation ROSATOM press service, hundreds gathered in Sarov for the funerals of five Russian nuclear engineers killed by the rocket explosion last week. (Russian State Atomic Energy Corporation ROSATOM via AP)

It has pledged to keep developing new weapons regardless, portraying the men who died in the test as heroes.

U.S. President Donald Trump said on Twitter on Monday the United States was "learning much" from the explosion which he suggested happened during the testing of a nuclear-powered cruise missile vaunted by President Vladimir Putin last year.

'Not good!': Trump takes note

Russia, which has said the missile will have an "unlimited range" and be able to overcome any defences, calls the missile the 9M730 Burevestnik (Storm Petrel). The NATO alliance has designated it the SSC-X-9 Skyfall.

Trump said on Twitter that the United States had "similar, though more advanced, technology" and said Russians were worried about the air quality around the facility and far beyond, a situation he described as "Not good!"

But when asked about his comments on Tuesday, the Kremlin said it, not the United States, was out in front when it came to developing new nuclear weapons.

"Our president has repeatedly said that Russian engineering in this sector significantly outstrips the level that other countries have managed to reach for the moment, and it is fairly unique," said Kremlin spokesperson Dmitry Peskov.

Putin used his state-of-the nation speech in 2018 to unveil what he described as a raft of invincible new nuclear weapons, including a nuclear-powered cruise missile, an underwater nuclear-powered drone and a laser weapon.

Tensions between Moscow and Washington over arms control have been exacerbated by the demise this month of a landmark nuclear treaty. Russia says it is also concerned that another landmark arms control treaty will soon expire.

Medics who treated victims of last week's accident have been sent to Moscow for a medical examination, the TASS news agency reported.

It said the medics had signed non-disclosure agreements about the nature of the accident.