The U.S. military is facing fresh concerns over its ability to fulfil operational obligations after it was revealed Tuesday in a Military News report that budget cuts have left the Navy without enough ships to take Marines to global hot spots. The revelation, which comes amid conflict over the national defense budget between the White House and Congress over how the Pentagon’s budget should be constructed, could force the Marines to either hitch rides on foreign ships or borrow them.

The Navy currently has 31 amphibious assaults ships, but needs as many as 38 in order to react to increased global obligations, in particular North Africa. But because of current budget constraints the Navy won’t be able to reach that number for another 13 years.

“Ceding our amphibious ships to other countries — it’s almost silly and I can’t believe it is even an option for the Navy,” said Rep. Duncan Hunter, R-Calif., who served as a Marine in Iraq. “Now we are going to have to ask other countries, much less financially stable countries than America, to loan us their ships so that we can base our Marines on their ships. It’s almost embarrassing.”

Jim Webb, former Secretary of the Navy under President Ronald Reagan until 1988, said that the Navy was too small, noting that when he left the job the total amount of ships was 568. That figure has more than halved to 280 today. “We are a maritime nation, and we communicate across the world through our sea services, and … the size of the Navy right now is way too low,” said Webb, who was a Marine infantry officer in Vietnam.

The U.S. Navy, however, has said that the move has less do with not having enough ships and more aimed at improving interoberability with its allies, including NATO.  “It’s always encouraging to be able to work with our allies and I would encourage increasing our interoperability,” said U.S. Navy Cmdr. William Marks, Chief of Navy Media. “With the inclusion of the joint high speed vessel, mobile landing platform and a float forward staging base, the navy is well positioned to meet marine corps needs.”

Part of the reasoning for this new approach is because of the new nature of disaster response and warfare. Marines are increasingly working in smaller numbers, far removed from the days of the Afghanistan and Iraq war when Marine Corp would be operating in the thousands. But to avoid using large amphibious assault vessels for just a small number of marines, the U.S. Navy and the Marine Corps have been looking at other options, including placing marines on allied ships that are already operating in the region.

And while the Marine corps is yet to comment on any specific plans to use foreign ships, the issue of not having enough amphibious assault vessels is unlikely to be solved anytime soon.

The U.S. National Defense Authorization Act, also known as the defense budget, has passed without fail for the past 53 years. However, under forced defense spending caps agreed in 2011 and delayed until 2016, next year’s budget has put the White House and Congress at odds and may see the  bill fail.

The White House wants to break spending caps for normal military spending and eliminate what’s known as the Overseas Contingency Operations Fund, or war fund – which is traditionally a fund that is used to fight official wars oversees and is exempt from spending limits. At its peak in 2007 it was at $211 billion. In the past it has been used by Congress to fund defense items that didn’t make it into the defense budget.

Congress, through the House and Senate Armed Service Committees, has voted to stay under the forced spending caps of $499 billion but wants to set the war fund at $89 billion to ensure it can pay for everything the military needs. If this version of the bill is presented to the White House, President Barack Obama has already said he will veto it because it would be unfair to other government departments that the Defense Department will be partially funded using a fund that does not adhere to spending limits.