The warning came as world powers and Iran gather in Vienna to salvage the 2015 nuclear deal after a five-month hiatus.
The United States has warned it is "prepared to use other options" including military force to ramp up pressure on Iran if nuclear talks fail.
The US National Security Council's coordinator for the Middle East and North Africa, Brett McGurk, issues the warning over the weekend, according to CNN.
"We are still hopeful that diplomacy can find a way, but if it cannot find a way, we are prepared to use other options," McGurk told the Manama Dialogue organised by the International Institute for Strategic Studies.
"When it comes to military force to prevent a country from obtaining a nuclear weapon, that is a very achievable objective," he added.
International talks on Iran's nuclear programme will restart in Vienna on Monday with analysts foreseeing major obstacles to any speedy resumption of the 2015 nuclear deal.
Along with Iran, diplomats from the UK, China, Germany, Russia and France will attend. The US will take part in the talks indirectly led by US Special Envoy to Iran Robert Malley.
Highly anticipated talks resume
US Special Envoy for Iran Rob Malley also warned that Washington and its partners are likely to exert pressure on Iran if it uses talks as pretext to accelerate its nuclear programme.
Failure to strike a deal could also prompt reaction from Israel which has said military options would be on the table. Tehran's new negotiating team has set out demands that US and European diplomats consider unrealistic, Western diplomats say.
They include insisting that all US and European Union sanctions imposed since 2017, including those unrelated to Iran's nuclear programme, be dropped
The talks paused in June on a positive note, with diplomats saying they were "close" to an agreement, but the arrival of ultraconservative Iranian President Ebrahim Raisi in office has changed the outlook.
The 2015 deal, also known as the Joint Comprehensive Plan of Action (JCPOA), offered a lifting of some of the array of economic sanctions Iran had been under in return for strict curbs on its nuclear programme.
But the deal began falling apart in 2018 when then US president Donald Trump pulled out and began reinstating sanctions on Iran.
IAEA Director General Rafael Grossi visited Tehran last week in the hope of addressing several bones of contention between the agency and Iran. However, he said on his return that "no progress" had been made on the issues he raised.