The Obama administration announced a series of executive actions Wednesday aimed at helping small businesses, countering Republican criticism that the president has not done enough in this important sector of the economy.

The initiatives would accelerate federal payments to contractors, reduce paperwork and increase access to investment capital, White House officials said. Obama also is calling on Congress to support a one-year extension of current legislation that allows companies to continue writing off $250,000 in investments on machinery and equipment.

Obama has recently come under renewed fire from the GOP, which says that burdensome federal regulations have hindered small business growth. This week, Obama called for a one-year extension of the George W. Bush-era tax cuts for families earning less than $250,000 a year, and Republicans charged that allowing the tax cuts to expire for everyone else would mean a tax hike for many small business owners.

“Small business is the backbone of our economy,” Jeffrey Zients, acting director of the Office of Management and Budget, said in a conference call. “It’s important that efforts to ensure that the government is . . . doing everything in its power to make it easier for small business to grow and hire.”

Under the executive actions, OMB would be required to pay contractors within 15 days, instead of 30, with the expectation that the contractors would also pay their smaller subcontractors more expeditiously. And the Small Business Administration would increase its small loan amount for companies to $350,000 from $250,000. The government also will streamline its application process to apply for surety bonds and disaster loans, the White House said.

Republicans weren’t impressed by the announcement, noting that the administration previously had announced the initiative to pay contractors more quickly.

“The White House has so little to offer small businesses they’ve resorted to recycling, reusing, and repackaging,” said Brendan Buck, spokesman for House Speaker John A. Boehner (R-Ohio).