CAMP DAVID, Md. — World leaders on Saturday declared Iran’s nuclear ambitions of “grave concern” and pointedly warned Tehran of tough sanctions against its oil program if it can’t convince the world it’s not seeking to produce nuclear weapons.

Gathering near here in the woody seclusion of the Camp David presidential retreat, leaders of the Group of Eight wealthy nations, acknowledging a global economy that faces “significant headwinds,” sought to portray togetherness, issuing a statement that said they were in agreement that Europe’s fragile economy needs a shot of growth, along with austerity measures.

Regarding Iran, the leaders said they “stand ready” to call on the International Energy Agency to ensure an adequate oil supply, given “increasing disruptions in the supply of oil to the global market over the past several months.”

The statement did not reference sanctions against Iranian oil, but it said that “looking ahead to the likelihood of further disruptions in oil sales,” the leaders were monitoring the situation and were prepared to ask the Paris-based agency _ which coordinates the release of the Global Strategic Petroleum Reserve, the crude oil stockpiled by the countries _ to “take appropriate action to ensure that the market is fully and timely supplied.”

The statement came hours after President Barack Obama declared the round of talks between leaders “fruitful” and noted they’d found common ground on a host of global hot spots, including Iran.

The regime’s “continuing violations of international rules and norms and its inability thus far to convince the world community that it is not pursuing the weaponization of nuclear power is something of grave concern to all of us,” Obama said.

He said leaders are hopeful about upcoming discussions in Baghdad, where the U.S. and five other countries have agreed to offer a proposal to Iran. But, he added, the countries are “firmly committed to continuing with the approach of sanctions and pressure.”

The meeting of the world’s richest democracies _ the U.S., the United Kingdom, Canada, France, Germany, Italy, Japan and Russia _ comes amid fears that Europe’s debt crisis could impair the U.S.’s slow recovery _ and complicate Obama’s re-election effort. Russian President Vladimir Putin did not attend.

“Against this background, we commit to take all necessary steps to strengthen and reinvigorate our economies and combat financial stresses, recognizing that the right measures are not the same for each of us,” the statement read.

The leaders said the global economic recovery “shows signs of promise, but significant headwinds persist.

Though Europe has pursued a strategy of strict belt-tightening, voter unrest evident in elections in France and Greece earlier this month has prompted a shift in accommodation, with leaders agreeing that some growth measures should be deployed.

Obama was to meet after the summit with German Chancellor Angela Merkel, who has pushed for tough austerity measures as she oversees most of the European recovery efforts.

The statement underscores the leaders’ interest in Greece “remaining in the eurozone, while respecting its commitments,” and acknowledges that the countries “all have an interest in the success of specific measures to strengthen the resilience of the eurozone and growth in Europe.”

There were no details on what the growth measures might look like, though the statement emphasizes “structural reforms, and investments in education and in modern infrastructure, as appropriate.”

It notes that investment initiatives could be financed through a variety of measures, including the private sector. Analysts have suggested leaders are going to need to come up with concrete steps soon to stem the financial morass that has gripped Greece.

White House officials said they were uncertain if more details would emerge during European talks next week, but they said European officials were “seized with the importance, the timeliness of addressing the issue.”

White House officials characterized the group’s statement on Iran as “unusual” and said it was the first time the G-8 had issued such a proclamation. It comes as a European Union embargo on purchases of Iranian oil is scheduled to take effect on July 1. Michael Froman, deputy national security adviser for international affairs, said it sends a signal that the countries are “determined to implement the sanctions fully,” as well as assure global markets that oil reserves would be “fully and adequately supplied during this critical time.”

He said there was no trigger point yet on when the countries might look to release oil from their reserves.

Though gas prices have recently declined, high gasoline prices could be problematic for Obama in the run-up to the election, and tapping the reserve is likely to open Obama up to criticism that he’s seeking a fix to a political problem.

Froman said the move wouldn’t be “an issue of price management, but of supply.”

The G-8 summit comes at a critical time for Obama _ six months before the election and amid a hornets’ nest of global problems that the leaders sought to address _ from Iran, North Korea and Syria to global hunger.

The White House moved the event from a “cavernous convention center” in Chicago _ where the NATO summit will open Sunday _ to the seclusion of Camp David in hopes of promoting more conversation among the leaders, without scripted talking points or motorcades. And White House officials said it paid off, describing world leaders taking casual walks in the woods and engaging in “unscripted and unplanned” conversations on cabin patios.

White House officials said the leaders actually marked up and wrote some of the statement, rather than relying on the “sherpas” _ as the staffers who pull together the events are called.

Obama got a chance to chat with British Prime Minister David Cameron while the two worked out on treadmills at the camp’s gym. Japanese Prime Minister Yoshihiko Noda was presented with a chocolate birthday cake on Friday night.

The room where the leaders met featured official White House photographs, including one that was likely hastily printed: a photograph of Obama and new French President Francois Hollande meeting for the first time Friday at the White House.

The participants dressed camp casual: Obama wore a dress shirt with the sleeves rolled up, his jacket slung on his chair. Other leaders were in V-neck sweaters or dress shirts without ties.

Despite the pastoral nature of the meeting, security remained world leader-tight. Marines repeatedly told reporters not to remove their cellphones from their pockets to photograph the presidential lodge.

“Everything for this family reunion was set up with military precision,” one pool report noted.