MUKACHEVO, UKRAINE — Russia and the West traded threats and diplomatic slights Wednesday, as another Russian deadline for Ukrainian forces to surrender the key port city of Mariupol passed without movement, and Moscow’s forces continued pummeling a broad swath of the country’s east.

Russia’s Defense Ministry announced that it had successfully conducted the first test of a new intercontinental ballistic missile that President Vladimir Putin said “is capable of overcoming all missile defense systems” and would make those who “try to threaten our country think twice.”

Putin also claimed, according to Russian news reports, that the nuclear-capable RS-28 Samrat missile was made using “exclusively” domestically manufactured parts — an apparent shot at Western sanctions, which have kept Moscow from obtaining critical components for other weapons systems it has relied upon in its assault on Ukraine.

Pentagon spokesman John Kirby said the United States, in keeping with existing arms control provisions, was notified of the test ahead of time. But Putin’s comments served as a reminder of the military might of his nuclear-armed state, and his potential willingness to escalate a brutal war that seems nowhere near an end.

Nine ways Russia botched its invasion of Ukraine

After the Ukraine invasion began, a test launch of a U.S. Minuteman III ICBM was postponed when U.S. officials said they did not want Russia to misconstrue such a display of firepower, or use it as justification to escalate hostilities in Ukraine.