WASHINGTON (United States)(National times)- US Vice President JD Vance told Iran Wednesday to take Washington’s threats of military action “seriously,” a day after President Donald Trump appeared to build the case for war in his State of the Union address. As US forces mass in the Middle East, Trump claimed in his speech to Congress on Tuesday that Iran was seeking to develop missiles that can strike the United States. Trump also accused the Islamic republic, whose negotiators will meet US officials in Geneva on Thursday, of having “sinister nuclear ambitions” and working to rebuild a nuclear program that was targeted by US strikes last year. Vance told Fox News that while Trump was going to try to “accomplish it diplomatically,” the US president also had the “right” to use military action. “You can’t let the craziest and worst regime in the world have nuclear weapons,” said Vance. “The president has a number of other tools at his disposal to ensure this doesn’t happen. He’s shown a willingness to use them and I hope the Iranians take it seriously in the negotiations tomorrow because that’s certainly what the president prefers.” His comments came as the United States announced fresh sanctions targeting Iran, pressing on with what Washington calls its “maximum pressure” campaign. Iran’s President Masoud Pezeshkian earlier struck an upbeat tone, saying there was a “favorable outlook” for the negotiations as his Foreign Minister Abbas Araghchi and his team left for Switzerland. Iran also rejected Trump’s claims about its missile program as “big lies.” But while Trump said he preferred a diplomatic solution, he also set out what appeared to be the justifications for possible military action in the first State of the Union address of his second term. It was the same forum in which then-president George W. Bush laid out the case for the invasion of Iraq in 2003. Trump claimed in his address that Tehran had “already developed missiles that can threaten Europe and our bases overseas, and they’re working to build missiles that will soon reach the United States of America”. Iran insists its nuclear program is for civilian purposes.