VICE PRESIDENT Joe Biden's older son, the Delaware attorney general, had a mild stroke yesterday and was transferred to a Philadelphia hospital, where he was alert and talking with family.

Beau Biden, 41, had been admitted to Christiana Hospital in Newark, Del., yesterday morning. Later in the day he was transferred to Thomas Jefferson University Hospital in Philadelphia, vice presidential spokeswoman Elizabeth Alexander said. The White House said earlier that he would undergo further observation and examination there.

Biden was expected to recover, his doctor said.

A Christiana Care ambulance arrived at Jefferson last night, escorted by more than a dozen Delaware and Pennsylvania state police and Philadelphia police cars. Hospital officials declined to comment, referring questions to the vice president's office.

Christiana Hospital's Timothy Gardner said Biden was in good spirits and was talking with his relatives. The doctor said in a statement issued through the White House that Biden was fully alert and in stable condition and had full motor and speech skills.

Jason Miller, Beau Biden's spokesman, had no immediate comment.

A state trooper had been stationed at the main entrance of the Delaware hospital, and several black SUVs and men in suits with earpieces were nearby.

Joe Biden's wife, Jill, was seen leaving the hospital about 4 p.m. Security-team members whisked her away before she could respond to questions.

The vice president had traveled to Delaware on Monday afternoon for a previously scheduled trip. He did a round of morning- show interviews from Wilmington yesterday morning, and was supposed to return to Washington later in the day for his weekly lunch with President Obama and a series of meetings on Afghanistan.

Jill Biden's scheduled tour of a women's health facility in Washington yesterday afternoon was postponed. Beau Biden had been scheduled to deliver a speech last night at the University of Delaware. Naturally, that was canceled too.

Beau Biden returned last year from a yearlong deployment to Iraq with his Army National Guard unit. He was a captain and military lawyer in the 261st Theater Tactical Signal Brigade.

He had considered running this year for the Senate seat his father held before becoming vice president, but decided instead to run for re-election as attorney general.

Delaware Gov. Jack Markell, a Democrat, said he wished Biden the best and declined to comment on how his health might affect the November election. "Everybody ought to be focused on him getting better," Markell said.

Beau Biden said when he announced his election plans in January that he needed to remain focused as attorney general on a high-profile criminal scandal involving a pediatrician accused of sexually assaulting dozens of patients. Prosecutors believe that Earl Bradley, who was arrested in December, may have molested more than 100 children over the past decade.

Biden's decision was a surprise, given that his father's longtime confidant and former Senate chief of staff, Ted Kaufman, was appointed to the seat essentially to keep it warm for the son until this year's election.

But longtime Republican Rep. Mike Castle, a two-term governor and one of the most successful politicians in Delaware history, entered the Senate race in October, dramatically increasing the likelihood of a fierce contest.

Beau Biden's decision left vulnerable the seat his father held for 36 years.

The elder Biden was away from that seat for seven months in 1988, after undergoing surgery for brain aneurysms.

More than a decade earlier, in 1972, he lost his wife and infant daughter when a tractor-trailer broadsided their station wagon when they were out getting a Christmas tree. Beau and his brother, Hunter, were critically injured but recovered.

The vice president devoted himself to caring for his two sons as a single father and still will not work on Dec. 18, the date it happened. The elder Biden seldom speaks of the tragedy, but remains sensitive about anything having to do with his children's welfare.

Beau Biden, who is married with two young children, has worked as an attorney in private practice. He also worked for the Justice Department between 1995 and 1997 and as an assistant U.S. attorney from 1997 to 2002.