Foreign ministers from the world's eight leading industrial nations have called for "appropriate and strong steps" against Iran over its nuclear activities.
The draft final communique drawn up during a two-day meeting in Canada on Monday did not specifically mention sanctions, but the United States, France and Britain have been pushing for a new round of restrictions in recent months.
"Iran's continued non-compliance with its UN Security Council and IAEA obligations regarding its nuclear programme is of serious concern to G8 ministers," the final communique said.
Tehran insists it has a right to nuclear technology and says its programme is simply designed to meet civilian energy needs. However, the US and its allies has repeatedly said they fear Iran is using the programme as a cover for weapons development.
The document is the latest step in attempts to force Iran to comply with demands from the UN Security Council to abandon its uranium enrichment programme and co-operate with the International Atomic Energy Agency (IAEA).
"Ministers agreed to remain open to dialogue and also reaffirmed the need for the international community to take appropriate and strong steps to demonstrate ... resolve to uphold the international nuclear non-proliferation regime," the communique said.
There have been increasing international calls for action since Tehran rejected an offer that would have seen it send it low-enriched uranium abroad in exchange for high-enriched fuel for use in reactors.
Mohammad Marandi, a professor of political science at Tehran University, said the problem is that the United States has too much influence over such issues.
"It's important to note that the vast majority of the countries of the world support Iran's nuclear programme - the Non-Aligned Movement, the Organisation of Islamic Conference - these constitute over two thirds of the countries of the world and they have repeatedly backed Iran's nuclear programme.
"This reinforces the argument that these issues are not with the international community, but it's the United States which wields a great deal of power and bullies other countries into accepting its policies of hostility against Iran and so the sanctions that have been placed on Iran are a result of Western pressure," Marandi said.
However, the support of China and Russia, both permanent members of the Security Council, would be key to pushing through any new sanctions.
China has repeatedly spoken out against fresh measures and called for more time to find a diplomatic solution to the standoff.
But Hillary Clinton, the US secretary of state, on Monday played down fears that Beijing was out of step with the other permanent members of the Security Council on the question of imposing more sanctions.
"China is part of the consultative group that has been unified all along the way, which has made it very clear that a nuclear-armed Iran is not acceptable to the international community," Clinton told Canada's CTV in an interview.
"I think as the weeks go forward and we begin the hard work of trying to come up with a Security Council resolution, China will be involved, they will be making their suggestions."
James Steinberg, the US deputy secretary of state, said in Washington that the United States was increasingly encouraged by the signs coming from Beijing.
"We've had a recognition by our Chinese counterparts of the danger of the Iranian nuclear programme and the fact that there does not seem to be a willingness [by] the Iranians to take the very generous offer," he said.
The White House later issued a brief statement saying Barack Obama, the US president, had met with the new Chinese envoy to Washington and told him the United States wanted to develop a positive relationship with Beijing.
Last Wednesday, China agreed to discuss a possible fourth round of sanctions against Iran for the first time , Britain's ambassador to the UN said.
Beijing, however, refused to confirm this, with Li Baodong, China's ambassador to the UN, saying simply: "For a long time China has been advocate of these talks.
"Now we are working along with other members, along with [the] international community, to find a peaceful solution to this issue."
Russia has also been unenthusiastic about sanctions, but Dmitry Medevedev, the president, recently said that they could be necessary to halt Iran's nuclear programme.
Clinton and other Obama administration officials have said they want the new sanctions to target Iranian companies and government elements like the country's Revolutionary Guard Corps and not the Iranian people.