Updated

Israeli President Shimon Peres was expected Wednesday to ask President Obama for the release of Jonathan Pollard, the American-turned-Israeli spy now serving a life sentence in U.S. prison.

Peres has made clear since arriving in the United States earlier this week that he will ask for clemency for Pollard, though not a pardon.

The Israeli president is in Washington to receive the Presidential Medal of Freedom. But he's decided to push the Pollard issue while he's in town, despite White House resistance -- Peres brought with him a strongly worded petition purportedly signed by 70,000 Israelis that states, “We urge you to use your exceptional diplomatic position to work for the immediate release of Jonathan. And (ask) before you receive your medal, which would otherwise make a mockery of Israel."

Peres told Fox News on Tuesday that Israelis “feel very strongly about (Pollard.) And I understand their sentiment. But I am doing it not as a diplomat ... but as a human being.”

His expected request comes amid increasing pressure to free the 57-year-old Pollard -- a civilian Navy analyst who was sentenced in 1987 for stealing secrets and whose health is reportedly failing.

The White House, though, does not seem likely to budge.

"Our position has not changed, and will not change today," White House Press Secretary Jay Carney said Wednesday. "Mr. Pollard was convicted of extremely serious crimes."

Reps. Chris Smith, R-N.J., and Eliot Engel, D-N.Y., are separately leading a bipartisan House effort to free Pollard by seeking signatures to a letter urging Obama to use his power of clemency to commute Pollard’s sentence to time served.

The lawmaker said in the letter that Pollard has severed his time.

“There is no doubt that he has paid a heavy price. And from the standpoint of either punishment or deterrence, we believe he has been imprisoned long enough,” the letter states.

Peres was scheduled to talk with Obama in the afternoon in a closed-door Oval Office meeting.

The meeting will be followed by an East Room dinner in which Peres in scheduled to receive the Presidential Medal of Freedom.

The White House calls Peres, elected in 2007, an “ardent advocate for Israel’s security and for peace.”