Top US diplomat John Kerry warns against deep budget cuts

The security assistance cuts could include $300 million in the Foreign Military Financing program and "lead to reductions in military assistance to Israel, Jordan and Egypt, undermining our commitment to their security at such a volatile time," wrote Kerry.

"This cut will be felt at home, resulting in a loss of sales to US industry and a potential loss of US jobs," he added.

Additional job losses would occur as budget cuts force the slower processing of visas for foreign tourists and business visitors, Kerry said.

The cuts would total about $85 billion this year across the entire US budget. With a deal to avoid them looking less and less likely, administration officials are rallying to warn of the pain that will be imposed on various programs.

Kerry also said cuts would impair efforts to beef up security at US diplomatic facilities, a sensitive issue after the attack by armed militants on the US mission in the Libyan city of Benghazi. US Ambassador Christopher Stevens and three other Americans were killed in that attack.

Americans living or traveling abroad would also feel the pinch, Kerry warned, as cuts "constrain our ability to assist US citizens overseas, often at their darkest times."