(Adds Attorney General Sessions statement, paragraphs 11-12)

WASHINGTON, April 26 (Reuters) - President Donald Trump on Wednesday attacked a federal judge's ruling that blocked his executive order seeking to withhold funds from "sanctuary cities" for illegal immigrants, vowing to appeal it to the U.S. Supreme Court.

Tuesday's ruling by U.S. District Judge William Orrick in San Francisco was the latest blow to Trump's efforts to toughen immigration enforcement. Federal courts have also blocked his two travel bans on citizens of mostly Muslim nations.

"First the Ninth Circuit rules against the ban & now it hits again on sanctuary cities-both ridiculous rulings. See you in the Supreme Court!" Trump said in a tweet on Wednesday, referring to the San Francisco-based federal appeals court and its judicial district.

The Trump administration has targeted sanctuary cities, which generally offer safe harbor to illegal immigrants and often do not use municipal funds or resources to advance the enforcement of federal immigration laws.

Later on Wednesday, Trump, asked in an interview with the Washington Examiner if he had considered proposals to break up the 9th Circuit Court, said: "Absolutely, I have."

"There are many people that want to break up the 9th Circuit. It's outrageous," he told the newspaper.

The latest ruling did not come from the 9th U.S. Circuit Court of Appeals to which Trump was referring. It came from the federal district court in San Francisco.

Critics have said local authorities endanger public safety when they decline to hand over for deportation illegal immigrants arrested for crimes, while supporters argue that enlisting police cooperation to round up immigrants for removal undermines trust in local police, particularly among Latinos.

Dozens of local governments and cities, including New York, Los Angeles and Chicago, have joined the "sanctuary" movement.

In his ruling, Orrick said Trump's Jan. 25 order targeted broad categories of federal funding for the sanctuary cities and that plaintiffs challenging it were likely to succeed in proving it unconstitutional.

'WILL CONTINUE TO LITIGATE'

U.S. Attorney General Jeff Sessions blasted Orrick's ruling, saying Trump's executive order was "squarely within the powers of the President."

"The Department of Justice cannot accept such a result, and as the President has made clear, we will continue to litigate this case to vindicate the rule of law," Sessions said in a statement.

An appeal is likely to be heard by the 9th Circuit before it goes to the Supreme Court. Republicans view the appeals court as biased toward liberals, and Trump was quick to attack its reputation in his tweets.