Washington, July 27 - Secretary of State Hillary Clinton has said that Iran will never achieve its goal of obtaining a nuclear weapon, declaring to Tehran: 'Your pursuit is futile.'

'What we want to do is to send a message to whoever is making these decisions, that if you're pursuing nuclear weapons for the purpose of intimidating, of projecting your power, we're not going to let that happen,' she said on NBC's 'Meet the Press' on Sunday.

'First, we're going to do everything we can to prevent you from ever getting a nuclear weapon. But your pursuit is futile, because we will never let Iran - nuclear-armed, not nuclear-armed.

'It is something that we view with great concern, and that's why we're doing everything we can to prevent that from ever happening. ... We believe, as a matter of policy, it is unacceptable for Iran to have nuclear weapons.'

Clinton said the Obama administration might still engage with Iran's regime, even though she thinks the people there 'deserve better than what they're getting.'

Asked if the US would be betraying Iran's democratic movement if the administration decides to negotiate with the government over its nuclear programme, she said: 'I don't think so.