WASHINGTON - The US military plans to send a large floating base for commando teams to the Middle East amid rising tensions with Iran and intensifying fighting in Yemen, The Washington Post reported Saturday.

Citing unspecified procurement documents, the newspaper said the Navy is converting an aging warship it had planned to decommission into a makeshift staging base for the commandos in response to requests from the US Central Command.

Unofficially dubbed a “mothership,” the floating base could accommodate smaller high-speed boats and helicopters commonly used by Navy SEALs, the report said. Special operations forces are a key part of President Barack Obama’s strategy to make the military leaner and more agile as the Pentagon confronts at least $487 billion in spending cuts over the next decade, the paper noted.

Mike Kafka, a spokesman for the Navy’s Fleet Forces Command, declined to elaborate on the floating base’s purpose or to say where, exactly, it will be deployed in the Middle East, The Post said.  Other Navy officials acknowledged that they were moving with unusual haste to complete the conversion and send the mothership to the region by early summer, the report said. Navy documents indicate that it could be headed to the Persian Gulf, where Iran has threatened to block the Strait of Hormuz, The Post noted.

Meanwhile, The Wall Street Journal reported late Friday the US military has concluded that its largest conventional bomb is not capable of destroying Iran’s most heavily fortified underground facilities suspected to be used for building nuclear weapons.

But citing unnamed US officials, the newspaper said the military was stepping up efforts to make it more powerful.

The 13.6-ton “bunker-buster” bomb, known as the Massive Ordnance Penetrator, was specifically designed to take out the hardened fortifications built by Iran and North Korea, the report said.

But initial tests indicated that the bomb, as currently configured, would not be capable of destroying some of Iran’s facilities, either because of their depth or because Tehran has added new fortifications to protect them, the paper noted.

Doubts about its bomb’s effectiveness prompted the Pentagon this month to secretly submit a request to Congress for funding to enhance the bomb’s ability to penetrate deeper into rock, concrete and steel before exploding, The Journal noted.

The Defence Department has spent about $330 million so far to develop about 20 of the bombs, which are built by Boeing Co., the report pointed out. The Pentagon is seeking about $82 million more to make the bomb more effective, The Journal said.

Defence Secretary Leon Panetta, in an interview with The Journal Thursday, acknowledged the bomb’s shortcomings against some of Iran’s deepest bunkers.

He said more development work would be done and that he expected the bomb to be ready to take on the deepest bunkers soon.

“We’re still trying to develop them,” Panetta said.