Iranian officials now speak openly about something long denied by Tehran as it enriches uranium at its closest-ever levels to weapons-grade material: The Islamic Republic is ready to build an atomic weapon at will.

The remarks could be bluster to force more bargaining-table concessions from the U.S. Without planning to seek the bomb. Or, as analysts warn, Iran could reach a point like North Korea did some 20 years ago where it decides having the ultimate weapon outweighs any further international sanctions.

All this could be put to the test Thursday as Iran, the U.S. And the European Union prepare for a snap summit that appears to be a last-ditch effort in Vienna to revive Tehran's tattered nuclear deal amid the new pressure. That includes one Iranian video online suggesting the country's ballistic missiles could “turn New York into a heap of rubble from hell.”

Hyperbole aside, the language taken as a whole marks a distinct verbal escalation from Tehran.

“In a few days we were able to enrich uranium up to 60% and we can easily produce 90% enriched uranium. ... Iran has the technical means to produce a nuclear bomb but there has been no decision by Iran to build one,” Kamal Kharrazi, an adviser to Supreme Leader Ayatollah Ali Khamenei, told Al Jazeera in mid-July. Uranium enriched at 90% is considered weapons-grade.

Ataollah Mohajerani, a culture minister under reformist President Mohammad Khatami, then wrote in Iran's Etemad daily newspaper that Kharrazi's announcement that Iran could make a nuclear weapon provided a “moral lesson” for Israel and President Joe Biden.