(CNSNews.com) - Leaders representing over 28 million evangelicals, Roman Catholics, and other Christians are calling for urgent action by Congress and key world leaders to prevent Iran from obtaining a nuclear weapon.  
 
“We urge your immediate action to address Iran’s program to develop and deploy nuclear weapons by imposing economic sanctions on foreign companies that: export refined petroleum products, including gasoline, to Iran; help maintain Iran’s domestic refining capacity; provide ships or shipping services to transport such products; underwrite those shipments; or finance or broker those shipments,” the leaders said in a letter issued Wednesday. 

The U.S., they said, should also immediately initiate a boycott of arms sales to Iran.
 
“For the world’s most dangerous regime to obtain the world’s most dangerous weapons is something that neither the United States nor the community of nations can allow,” the leaders told Congress.
 
In a speech late Wedneday to the United Naitons General Assembly in New York, Iranian President Mahmoud Ahmadinejad made no mention of his country’s nuclear program, choosing instead to focus his attention on Israel.
 
"How can crimes of the occupiers against defenseless women and children and destruction of their homes, farms, hospitals and schools be supported unconditionally by certain governments?" Ahamadinejad asked.
 
But the Iranian leader ominously said it was time for the world to “respond” to the Jewish state.
 
"It is no longer acceptable that a small minority would dominate the politics, economy and culture of major parts of the world by its complicated networks, and establish a new form of slavery, and harm the reputation of other nations, even European nations and the U.S., to attain its racist ambitions," he said.
 
Ralph Reed, chairman of the Faith and Freedom Coalition, told CNSNews.com that the letter couldn’t be more timely:
 
-- talks are scheduled to begin with Iranian diplomats on Oct. 1;
-- Secretary of State Hillary Clinton is set to lead the U.S. delegation at a biannual conference on the Comprehensive Nuclear Test Ban Treaty (CTBT) today and tomorrow in New York;
-- and President Obama, who also addressed the U.N. Wednesday, will chair a meeting of the U.N. Security Council today on disarmament and nuclear nonproliferation.
 
“Cut to the chase: we’re at a critical juncture here,” Reed said. “This administration set a Sept. 15 deadline for a substantive response from Iran regarding its nuclear activity. That deadline has now passed. This is a very delicate and timely moment for such a statement from the faith community to be made,” Reed told CNSNews.com
 
A total embargo and a cut-off of exports of refined petroleum products, including gasoline, are firm yet peaceful measures against Iran, listed as one the world’s leading state sponsors of terrorism, Reed said. Although Iran has large oil reserves, it has been unable to refine its petroleum products and is vulnerable to such sanctions, he said.
 
“Iran has amply demonstrated its intransigence in the face of soft diplomacy, and it is past time the United States showed leadership in demonstrating to the Iranian government that there are serious and sustained consequences for the course of action on which it has embarked,” the letter added. 
 
In his maiden speech Wednesday before the United Nations, President Barack Obama only indirectly referred to Iran.
 
"The religious convictions that we hold in our hearts can forge new bonds among people, or tear us apart,” he said, “The technology we harness can light the path to peace, or forever darken it. The energy we use can sustain our planet, or destroy it. What happens to the hope of a single child anywhere - can enrich our world, or impoverish it.”

Reed, meanwhile,  said the Christian leaders expect their letter will be welcome on Capitol Hill, at least.
 
“Two thirds of the members of the Senate and the House are already co-sponsoring legislation that would achieve two of the aims mentioned in this letter – namely a total arms embargo on Iran and a cut-off of petroleum product imports into Iran,” he added.
 
The leaders include Bill Donohue of the Catholic League for Religious and Civil Rights; Pat Robertson of Christian Broadcasting Network; Southern Baptist Convention chairman and pastor Johnny Hunt; Chuck Colson of Prison Fellowship; Richard Land of the Ethics and Religious Liberty Commission of the Southern Baptist Convention; Dr. Michael Youssef of Leading the Way; Wendy Wright of Concerned Women for America; Gary Bauer of American Values and John Hagee of Cornerstone Church in San Antonio.