Britain will not be taking sides in Iran's internal politics, Jack Straw has said.
The foreign secretary was on Monday delivering a keynote speech setting out a softer approach to the Iranian regime.
His comments came as the United Nations security council was set to begin discussing the next steps in dealing with Tehran's nuclear programme.
The keynote policy statement also appears at odds with the US stance, with the administration saying it will actively push for greater democracy in the country.
Straw said Britain would also continue to speak out on human rights.
But he added: "We will not take sides in Iran's internal political debates, those are for the Iranians to resolve."
Addressing the nuclear issue, Straw said the concern was not centred on power generation.
"The concern of the international community does not stem from the desire to stop Iran generating electricity from nuclear power - in fact, we offer support for the development of civil nuclear power generation," the foreign secretary told the International Institute for Strategic Studies.
And the international community should "leave the door open for negotiations with Iran at any stage", he added.
"Security council involvement does not mean an end to our efforts to find a negotiated solution. It marks a new phase in diplomatic efforts."
But Straw also warned Tehran that they were heading in "the wrong direction".
"The chances that Iran has to capitalise on the fact that they no longer have a belligerent dictator on their doorstep in Iraq nor an aggressive Taliban in Afghanistan are being squandered," he said.
"We in the rest of the international community should not look the other way when the regime fails to abide by international standards in the way it treats its people.
"This does not mean that we should stop standing up for the principles of human rights and fundamental freedoms which we hold dear to ourselves and which so many Iranians aspire to.
"Our message is that we want the Iranian people to enjoy the benefits of civil nuclear power and we support their aspirations for a freer, more democratic and prosperous Iran."
