WASHINGTON — President Joe Biden is nominating Comcast executive and top political fund-raiser David L. Cohen to serve as his ambassador to Canada, the White House said Wednesday. He’s also naming Victoria Kennedy, an attorney and the widow of Sen. Ted Kennedy, to serve as his ambassador to Austria.

Cohen’s international departure would continue his trajectory as a master of behind-the-scenes politicking in increasingly broad arenas.

He was chief of staff when Ed Rendell was Philadelphia mayor, helping pull the city away from the brink of bankruptcy in the early 1990s. Cohen has been a fixture in Philadelphia’s political, business, philanthropic, and educational worlds ever since, later becoming an executive vice president of Comcast. He was one of Biden’s top “bundlers” of campaign donations, and his Mount Airy home became a regular fund-raising stop for former President Barack Obama and then Biden.

Cohen also became a consummate Washington insider for Comcast, leading high-stakes efforts such as securing regulatory approval for the company’s acquisition of NBCUniversal.

He has stepped back from his role at Comcast, transitioning from executive vice president to senior adviser to CEO Brian Roberts.

Cohen said in a statement that, if confirmed, he would look to grow “what is a very strong and important relationship as we continue to fight the pandemic and build our economies back stronger.”

Canada announced this week that it would ease restrictions at the border next month, allowing U.S. citizens and permanent residents living in the United States who are fully vaccinated to enter without quarantining. The U.S. government on Wednesday extended the closure of the land borders with Canada and Mexico to non-essential travelers until at least Aug. 21.

Sen. Pat Toomey (R., Pa.) hailed Cohen’s nomination as “an outstanding decision” by Biden.

”David’s global business acumen and decades of experience on the world stage will undoubtedly serve him well in this important role,” Toomey said.

Kennedy, a gun control advocate, came to know the president during the years when Biden served with her husband in the Senate.

She is the president of the board and co-founder of the Edward M. Kennedy Institute for the United States Senate, a nonpartisan nonprofit that educates the public about the U.S. Senate, and also leads the education committee of the board of trustees for the Kennedy Center in Washington.

Kennedy has also served on the boards of gun control advocacy groups, the Brady Center to Prevent Gun Violence in Washington, D.C., as well as Stop Handgun Violence in Boston. She founded the group Common Sense about Kids and Guns, aimed at reducing guns deaths and injuries to children.

“My parents and grandparents taught us through the example of their own lives how important it is to serve and give back,” Kennedy said in a statement. “And my late husband, and his extended family, embodied the noblest qualities of service to country. I am humbled by the confidence the President has placed in me, and if confirmed, I look forward to being able to serve my country as ambassador to Austria.”

Biden is also giving serious consideration to another member of the Kennedy family.

Caroline Kennedy, the daughter of President John F. Kennedy who served as ambassador to Japan during the Obama administration, is being weighed as a contender to serve in a high-profile ambassadorial role -- perhaps in Asia or Australia, according to a person familiar with the deliberations who was not authorized to comment.

The White House also announced that Biden was nominating Jamie Harpootlian, a South Carolina attorney and influential Democrat in the early primary state, to serve as his ambassador to Slovenia. She is married to another powerful South Carolina Democratic operative and Biden ally, state Sen. Dick Harpootlian.

The president’s victory in the South Carolina primary turned out to be the turning point for a campaign that struggled out of the gate.

-Staff writer Jonathan Tamari contributed to this article.