SAN FRANCISCO (Reuters) - The U.S. Department of Justice said a federal court should not suspend President Donald Trump’s executive order that seeks to withhold federal funds from so-called sanctuary cities for immigrants.

Trump in January signed an order targeting local governments that limit cooperation with federal immigration authorities, as he made plans to transform how the United States deals with immigration and national security.

Santa Clara County, which includes the city of San Jose and several smaller Silicon Valley communities, asked a federal judge to issue a nationwide injunction against the ban, saying Trump’s plan has thrown its budgeting process into “disarray.” The city of San Francisco filed a similar request.

In a court filing on Thursday, the Justice Department said the federal government still has more work to do before it decides exactly how it would implement Trump’s order, and what funds might be in dispute.

To win a nationwide injunction, the local governments must demonstrate a high level of harm and mere budget uncertainty doesn’t meet the bar, the Justice Department said.

“Governmental budgeting always suffers from some amount of uncertainty, in relation to both costs (which are based on services provided) and income (which is based in part on tax revenues),” DOJ said in the filing.

Cody Harris, an attorney representing Santa Clara county, said in an email the Justice Department’s arguments “are remarkably thin, and ignore both the facts and the law.”

Harris said the county looks forward to arguing the issues before U.S. District Judge William Orrick III in San Francisco next month.

The county has said it receives roughly $1.7 billion in federal and federally dependent funds each year, about 35 percent of its total annual revenues.

Republican Trump has vowed to get tougher on the estimated 11 million illegal immigrants in the United States than his Democratic predecessor Barack Obama. Protesters have taken to the streets in opposition to Trump’s plans and organized events such as “A Day Without Immigrants” last month to highlight the importance of foreign-born people to the economy.