Supreme Court Chief Justice John Roberts has called on Congress to increase the budgets of the federal judiciary, saying a shortage of money "remains the single most important issue facing the courts."

"I would like to choose a fresher topic, but duty calls," said Roberts in his annual year-end report.

He added that failing to adequately fund the federal judiciary "undermines the public’s confidence in all three branches of government."

While the court system is an independent branch of the federal government, it relies on funding from Congress. Court officials on Dec. 5 asked Congress to allocate $7.04 billion for the judiciary for the rest of the 2014 fiscal year, which runs through September. That is less less than two-tenths of 1 percent of total federal outlays.

The request includes $5.05 billion for the salaries and expenses for court operations nationwide.

The American Bar Association says the federal judiciary's budget for fiscal 2013 was $6.62 billion -- a $350 million reduction from the previous year that was due to the federal sequestration cuts.

Roberts said the courts were hurt more by the sequestration cuts than elsewhere in the federal government because "virtually all of [the judiciary's] core functions are constitutionally and statutorily required."

The cuts mean the courts now have fewer clerks, probation and pretrial officers and public defenders, and less funding for security guards, he said.

"The nation needs a balanced financial ledger to remain strong at home and abroad," Roberts said. "We do not consider ourselves immune from the fiscal constraints that affect every department of government. But … the independent judicial branch consumes only the tiniest sliver of federal revenues."

Roberts said the courts have been cutting costs for a decade.

"Court administrators squeeze as much as they can from every dollar," he said. We "recognize our obligations and are committed to doing our part in reducing federal expenditures."

Congress in December approved an overall federal budget for the rest of the 2014 fiscal year. But congressional appropriators are currently working to specify exactly how the money will be spent.

"In the coming weeks, and into the future, I encourage the president and Congress to be attentive to the needs of the judicial branch and avert the adverse consequences that would result from funding the judiciary below its minimal needs," Roberts said.

"The judiciary continues to depend on the vision and statesmanship of our colleagues in the Executive and legislative departments."