U.S. Senate candidate Joe Arpaio has repeatedly pledged his unwavering support for President Donald Trump, but the divisive retired sheriff is unwilling or unable to elaborate on the president's policies. Arpaio declined at a news conference Tuesday to explain how Mr. Trump's earlier plan to impose tariffs on Chinese imports would affect Arizona residents and whether the withdrawal from the Iran nuclear deal would make Americans less or more safe.

Instead, he focused on his loyalty to Mr. Trump, who nine months ago pardoned Arpaio's criminal contempt-of-court conviction for intentionally disobeying a judge's order in an immigration case.

"I am not a 'yes man,' but I do support the majority of his policies, his agenda, and I'm going to continue doing that," Arpaio said. He was unable to name any Trump policies he opposed.

The 85-year-old lawman, who lost his 2016 re-election campaign to a little-known Phoenix police sergeant as his legal problems mounted, spoke to reporters Tuesday before handing in petition signatures needed to compete in the Aug. 28 Republican primary in the race to replace retiring Sen. Jeff Flake.

Get Breaking News Delivered to Your Inbox

Arpaio faces U.S. Rep. Martha McSally and former state Sen. Kelli Ward in the GOP field.

Former Arizona Sheriff Joe Arpaio has collected enough signatures to get his name on the ballot to run in the race to succeed retiring U.S. Sen. Jeff Flake. The controversial Republican lawman faces two GOP challengers in the Aug. 28 primary.

In his 24 years as metro Phoenix's sheriff, Arpaio wasn't known for immersing himself in the policies and inner workings of his office and often prided himself on farming out those details to his underlings.

Now, Arpaio is facing tough questions about the details of his beliefs. Those questions led to tense exchanges between Arpaio and reporters shortly before he turned in the signatures.

Asked to say how the tariffs threatened by Mr. Trump would affect Arizona residents, Arpaio said only that he wants products to be made in the United States and doesn't believe the approach to tariffs would hurt the state.

He also was asked whether he knew what a tariff was.

"I know what tariffs are, but I'm not here to do a history — to educate you on what a tariff is," Arpaio said.

Similarly, he declined to say whether the Iran nuclear deal would make the United States safer.

"I don't have all the foreign information," Arpaio said. "You expect me to know everything. I am not in the Senate yet."

Arpaio, who was known for launching dozens of crackdowns on immigrants as sheriff, bristled when asked about taxpayers' rising bill from his traffic patrols that targeted immigrants.

Taxpayers in Arizona's most populous county have shelled out nearly $88 million over the last five years to cover legal and compliance costs in a racial profiling lawsuit that focused on his immigration patrols. Arpaio lost the case, and a judge ordered a massive overhaul of the agency.

The cost to taxpayers is projected to reach $120 million by summer 2019.

Arpaio rejected suggestions that he is to blame for the unexpected costs that arose from his patrols. He blamed the costs on the U.S. judge who ruled that Arpaio's officers had racially profiled Latinos in the patrols and found that the sheriff had ignored his order to stop the tactic.

"It's not my fault. I am not guilty," Arpaio said.