DENVER -- Saying uncertain economic times require tough measures, Gov. Bill Ritter on Thursday announced a freeze on hiring new state employees and ordered a halt to new construction.

Ritter said the situation has changed since Monday, when he said it was too early to begin slashing the state budget before Congress approves a bailout of the financial industry.

Among the first items to be cut was a plan to spend $30 million for full-day kindergarten construction projects and $50 million for capital construction projects that were approved but not under way.

Ritter said he was persuaded to change his mind by a grim speech by President George W. Bush about the country's economic future if a bailout agreement is delayed. He said it's only prudent for the state to begin cutting back now to be prepared if revenues decline.

"These are uncertain economic times. Every day, seemingly every hour, we hear about another fund or another lender that is on the brink of financial ruin. However, even in these challenging times I remain optimistic.

"But we must be responsible stewards of taxpayer dollars. Colorado is not immune from what's happening around us. We must be prudent and we must be thoughtful in our planning. We must take steps now to ensure that we have options should state revenues begin to dramatically decline," Ritter said at a hastily called news conference at the Capitol Thursday afternoon.

He repeated the word "prudent" several times, saying Colorado's budget is stable and strong but it was time to make major, prudent cuts.

"These are prudent actions that we believe will ensure we have options should the crisis in the financial industry on Wall Street have large impacts on our state economy. During the months ahead, if it appears any of these actions are not needed I will repeal them," Ritter said.

Ritter said state agencies will be able to hire people only if the person has accepted a position by Monday. He said it will not apply to workers critical to protecting life, health and safety.

Ritter said it will not apply to institutions of higher education, the Colorado Department of Education and departments headed by other statewide elected officials, although he encouraged those officials to take similar steps.

The University of Colorado System said it was reviewing the governor's order.

"As we have in the past, we will work closely with the governor to do our part to help Colorado address its fiscal challenges," CU President Bruce Benson said in a written release.

Ritter said he has no idea how many new state jobs are at stake or how much money will be saved by the hiring freeze. However, he projected that halting construction through Jan 31, 2009 could save $85 million.

"I want to be clear I am taking these actions to keep our options open, protect taxpayer dollars and to ensure that we can provide essential services," Ritter said.

Republicans were quick to criticize, saying Ritter rejected requests during the last session that ended in May to set up a rainy day fund to protect the state in any economic downturn and to delay major new projects.

Ritter held firm as early as Monday, when lawmakers on the Joint Budget Committee warned that the latest revenue forecasts predicted a $100 million shortfall this year. Ritter said estimates from his budget office indicated there would be no shortfall. On Thursday, he said the economy is still doing far better than the national economy.

Sen. Mike Kopp, R-Aurora, said it's up to the governor to figure out where to make the cuts now because the Legislature won't return until January, unless the governor calls a special session or lawmakers call themselves back.

"We of course predicted this was happening. We should have done this during the budget debate," Kopp said.

"The unfortunate thing is that this was completely avoidable. A hiring freeze wouldn't be necessary if the Democrats had not just added an additional 1334 positions to state government in March. The record-setting $18 billion state budget plan was passed over Republican objections and was completely void of fiscal responsibility. But if the governor is finally willing to have a realistic conversation about our economy and our budget, we certainly welcome him to the table," said House Minority Leader Michael May, R-Parker.