NEWARK, N.J. - Amid a federal investigation, U.S. Sen. Bob Menendez insists he has always been honest in his more than 20 years in Congress and says he is "not going anywhere" even as a person familiar with the matter says he's expected to face criminal charges soon.

The New Jersey Democrat has been dogged by questions about his relationship with a Florida doctor and political donor, whose office was raided by authorities two years ago. Now charges are expected to be filed against Menendez in the coming weeks, according to the person who spoke to The Associated Press on condition of anonymity because the investigation is pending.

Attorney General Eric Holder declined to say whether he has authorized criminal charges against the senator.

At a news conference Friday in his home state, Menendez spoke in English and Spanish, chopping his hand down for emphasis.

"Let me be very clear, I have always conducted myself appropriately and in accordance with the law," he said. "Every action that I and my office have taken for the last 23 years that I have been privileged to be in the United States Congress has been based on pursuing the best policies for the people of New Jersey and this entire country."

He said he couldn't take questions "because there is an ongoing inquiry."

Menendez, who served for more than a decade in the House of Representatives before joining the Senate in 2006, is the top Democrat on the Senate Foreign Relations Committee. He has been critical of negotiations between President Barack Obama's administration and Iran on its nuclear program and outspoken in opposition to normalizing relations with Cuba.

Iranian media gave extensive coverage to story. "Financial Corruption of Anti-Iran Senator" was the headline from the official IRNA news agency. The semi-official ISNA news agency described Menendez as "one of the most prominent American senators opposed to nuclear talks with Iran."

Scrutiny of his ties to Dr. Salomon Melgen, an ophthalmologist, has focused on trips Menendez took to the Dominican Republic aboard Melgen's private plane. He has acknowledged taking several actions that could have appeared to benefit Melgen, including contacting a Medicare agency to urge changes to a payment policy that had cost Melgen millions of dollars.

Menendez said he has been friends with Melgen for two decades.