Vice President JD Vance has said the Iran ceasefire is a "fragile truce."
The ceasefire, announced Tuesday, halted attacks on the country for two weeks and triggered a relief rally in global markets.
Speaking in Hungary, Vance said Wednesday that Iran's foreign minister had responded well to the ceasefire but others in the country had been "lying" about the agreement.
"This is why I say this is a fragile truce," he said. "You have people who clearly want to come to the negotiating table and work with us to find a good deal, and then you have people who are lying about even the fragile truce that we've already struck."
Vance, who has been campaigning for Hungarian Prime Minister Viktor Orbán's re-election, said the U.S. had "clear military, diplomatic and, maybe most importantly, we have extraordinary economic leverage" over Iran.
"The President has told us not to use those tools. He's told us to come to the negotiating table. But if the Iranians don't do the exact same thing, they're going to find out that the President of the United States is not one to mess around. He's impatient. He's impatient to make progress," Vance added.
U.S President Donald Trump threatened earlier this week that a "whole civilization will die" without a deal for a ceasefire. He warned Iran had to either cut a deal or face massive strikes on its civilian infrastructure.
This is a developing story. Please check back for updates.