US President Joe Biden orders his staff to prepare "additional measures" if troubled talks over Iran's nuclear programme, which resumed in Vienna, fail to reach a resolution.
The United States has said that it is reviewing its options in case troubled talks over Iran's nuclear programme fail.
"The president has asked his team to be prepared in the event that diplomacy fails and we must turn to other options," White House Press Secretary Jen Psaki told reporters on Thursday.
"If diplomacy cannot get on track soon and if Iran's nuclear programme continues to accelerate, then we will have no choice but to take additional measures to further restrict Iran's revenue-producing sectors."
The US warning came as negotiations between Iran and world powers aimed at salvaging a tattered 2015 nuclear deal resumed in Vienna after a few days' pause.
Meanwhile, US special envoy for Iran Robert Malley told Al Jazeera TV that the United States was ready to hold direct negotiations with the Iranians, calling it the best solution to such a complicated issue.
Malley added that Iran did not present constructive proposals during previous negotiations and even retracted compromises it had made before.
Israel keen on military readiness
Also on Thursday, the US and Israeli military leaders voiced strong concern at a Pentagon meeting about Iran's nuclear advances, with Israel expressing a goal of deepening dialogue on joint military readiness to be able to halt Iran's regional aggression and nuclear aspirations.
US Defense Secretary Lloyd Austin said he was deeply concerned about Iran's lack of constructive diplomatic engagement.
Reuters, citing a senior US official, exclusively reported that Thursday's US-Israeli agenda was expected to include discussions about possible military exercises that would prepare for a worst-case scenario to destroy Iran's nuclear facilities should diplomacy fail.
Talks in Vienna are going on between Iran and the five powers still in 2015 deal –– Britain, China, France, Germany, and Russia - following then-president Donald Trump's 2018 decision to unilaterally withdraw the United States.
Under the accord, Iran curbed its nuclear programme in return for relief from economic sanctions.
An American delegation plans to take part indirectly in the coming days.