Foreign ministers from the Group of Eight leading industrial nations will call on the international community to take "appropriate and strong steps" to show its resolve over Iran's nuclear activities, as they end their two-day meeting in Canada on Tuesday.
A draft of the final communique also said the G8 remained open to dialogue with Tehran, which denies widespread western charges that it is seeking to make atomic weapons.
The communique is the latest step in a campaign of pressure by many of the world's most powerful nations to force Iran to comply with demands from the U.N. Security Council and cooperate with the International Atomic Energy Agency.
Iran insists its nuclear program is for peaceful purposes.
"Iran's continued noncompliance with its United Nations Security Council and IAEA obligations regarding its nuclear program is of serious concern to G8 ministers," said the final communique.
"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 nonproliferation regime."
The draft did not mention the word "sanctions."
The three Western members of the Security Council -- the United States, France and Britain -- along with Germany have been pushing hard for a new round of sanctions against Iran.
Russia has been less enthusiastic but has recently signaled it may come on board. But China, which enjoys close economic links to Iran, has repeatedly said that the world needs more time to find a diplomatic solution to the standoff.
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
U.S. State Secretary Hillary Clinton
Earlier on Monday, U.S. Secretary of State Hillary Clinton played down fears China 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.
The White House issued a brief statement late on Monday saying President Barack Obama had met with the new Chinese envoy to Washington and told him the United States wanted to develop a "positive relationship" with Beijing.
Momentum for new sanctions has gathered steam since Tehran rejected an offer of a nuclear fuel swap deal that would have been brokered by the IAEA.
U.S. Deputy Secretary of State James Steinberg, speaking to reporters in Washington, said 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 program and the fact that there does not seem to be a willingness (by) the Iranians to take the very generous offer," he said.
The G8 meeting was also expected to take up other issues including the impasse over North Korea's nuclear program, nuclear nonproliferation, and the threat posed by extremist groups -- underscored by Monday's suicide bomb attacks that killed 38 in Moscow metro stations.
The G8 ministers released a statement strongly condemning the "cowardly terrorist attacks" and calling for those responsible to be brought to justice.
Iran's continued noncompliance with its United Nations Security Council and IAEA obligations regarding its nuclear program is of serious concern to G8 ministers
G8 final communique