Homeland Security Secretary Michael Chertoff pledged Friday that the government would help California patch its fragile levee system, but stopped short of promising the pre-emptive federal disaster declaration that Gov. Arnold Schwarzenegger seeks.

"We obviously do want to stand with the state in terms of getting engineering assistance and the money to help the state do what it has to do," Chertoff said. "And we want to make sure we can cut through red tape in terms of getting it done."

Bush administration officials said privately that such an extraordinary disaster declaration — before any levees failed — was unlikely. But they said the federal government was exploring other ways to help, including assembling response plans and possibly tearing down bureaucratic rules that some believe are hampering the repairs.

"If tomorrow we have a levee break, we need to have a plan in place," Chertoff said at the Commonwealth Club in San Francisco. "We're doing that as we speak."

Chertoff accompanied Schwarzenegger on an aerial tour of the levees — part of what Bush administration officials called a fact-finding tour. The visit came about three weeks after the governor declared a California state emergency to hasten repairs to weakened levees in the Central Valley. That order suspended state environmental and contracting rules that could slow the work.

A San Francisco firm, URS Corp., has been hired to oversee repairs to 24 critical sites in the Central Valley where erosion could cause the levees to collapse. Those repairs are expected to cost $75 million to $100 million.

The 1,600 miles of federal-state levees protect farms and homes throughout the Sacramento-San Joaquin Delta and along the rivers that flow into it.

Largely because of weaknesses in the levees — some built more than a century ago — parts of the Sacramento region have less than 100-year flood protection, the lowest of any large urban area in the nation. That's led to fears that an earthquake or flood could cause a Katrina-type catastrophe and jeopardize the water supply for 22 million people.

In a letter to President Bush three days after his emergency declaration, Schwarzenegger said the federal share would be at least $56 million.

The state needs a federal declaration to ease federal environmental reviews that also could slow down the work. Without it, the governor said, repairs will take three years instead of one.

Schwarzenegger also was counting on $3 billion in federal money for levee repairs as part of the infrastructure bond he announced during his state of the state address in January.

U.S. Sen. Dianne Feinstein this month said the money is unlikely to materialize. Schwarzenegger then amended his public works proposal to seek an additional $3.5 billion in voter-approved bond money for the levee work.

The governor had hoped to place a wide-ranging public works bond on the June ballot, but the plan fizzled this week when lawmakers failed to reach a compromise.

From Sacramento, Chertoff flew on a U.S. Coast Guard helicopter to the Port of Oakland, the fourth-busiest U.S. port with $33 billion in goods moving through its terminals annually.

The Port of Oakland is the first in the country to screen all cargo for radioactivity. "We know the thing that most scares people, and rightfully so, is the idea of a container as the vehicle for something so destructive that it would be devastating to this country," he said.

Two-thirds of all cargo entering American ports is tested for radioactivity and by next year "essentially 100 percent" of all cargo will be tested, Chertoff said.

Unlike the six ports in the scuttled Dubai deal, the Port of Oakland is managed by the City of Oakland, although several terminals are leased to overseas companies.

Chertoff made only indirect reference to the Dubai ports-management deal in remarks to reporters in Oakland.

"Port security's been in the news a lot but we've been talking about port security for a couple years now," he said.