WASHINGTON - The US military said on Monday it wants to speed up production plans for an enormous "bunker buster" bomb, amid international concern over underground nuclear sites in Iran and North Korea.
The Pentagon has asked Congress for extra money to ensure the massive ordnance penetrator (MOP) would be ready by July 2010, spokesman Bryan Whitman told reporters.
"The department has asked for reprogramming of about 68 million dollars to start production for some of these in 2009," Whitman said.
"This will help it accelerate some if it's approved."
The weapon, weighing in at 30,000 pounds (13,600 kilograms) and carrying 5,300 pounds (2,400 kilograms) of explosives, would be delivered by the radar-evading B-2 Stealth bomber.
The MOP, believed capable of blasting through 200 feet (60 meters) of reinforced concrete, is seen as a potential weapon against nuclear facilities in Iran and North Korea that are mostly buried underground.
Washington has demanded that both countries abandon their nuclear programs and has refused to rule out possible military action.
Whitman declined to say why the military wanted to accelerate production or whether the move was designed to pile pressure on Iran.
He said the Pentagon since 2004 had been looking at developing weapons "that would allow us to go after more hardened, more deeply buried targets."
He mentioned that Pyongyang has sought to conceal its nuclear activities. "One of the ways you hide is by going underground" and fortifying sites, he said.
Boeing builds the MOP, which could become the biggest conventional bomb ever used by the US military.
During a visit to the Middle East last week, US Defense Secretary Robert Gates warned that Washington's diplomatic outreach to Iran was not open-ended and said Tehran had until September to respond or else face tougher sanctions.
The United States, European states and Israel, widely considered the Middle East's sole -- if undeclared -- nuclear power, suspect Iran is trying to develop atomic weapons under the guise of a civilian nuclear program, a charge Tehran has denied.
In an interview last month, President Barack Obama strongly denied that the United States had given Israel a green light to strike Iran's nuclear sites.
Tensions on the Korean peninsula meanwhile have soared following Pyongyang's recent missile and nuclear tests, which resulted in fresh UN sanctions and a renewed standoff with the United States.