Sen. John Kerry, who was nominated by President Barack Obama last week to replace Hillary Clinton as U.S. Secretary of State, has released a statement supporting U.S. Rep. Ed Markey (D-Malden) as his replacement, a day after Markey announced his candidacy.

Kerry's staff wouldn't explicitly call the statement an endorsement, though a a Kerry aide did say Kerry will be voting for Markey.

"While I began last week to formally step out of politics and it's very important that I respect the apolitical nature of the post I hope to soon occupy, as Massachusetts' senior senator today and as a colleague of Ed Markey's for 28 years, I'm excited to learn of and support his decision to run for the United States Senate,” Kerry said in a statement. “Ed's one of the most experienced and capable legislators in the entire Congress and it would be an almost unprecedented occasion for such an accomplished legislator to join the Senate able to hit the ground running on every issue of importance to Massachusetts."

"Ed's someone who authored and passed a visionary energy bill to deal with climate change; he's one of Congress' foremost experts on the Internet, telecommunications and new energy economies; he was a leader on nuclear weapons issues; and he's the House's leading, ardent, and thoughtful protector of the environment," Kerry said. "Ed's upbringing in Malden and his service as the Dean of our delegation means he knows in his heart and in his head just what is important to every corner of our state. He's passionate about the issues that Ted Kennedy and I worked on as a team for decades, whether it's health care or the environment and energy or education. He's gutsy and tough, smart and sharp, a workhorse in Congress who has never forgotten where he came from or who sent him to Washington."

Boston University political historian Thomas Whalen said the statement gave Markey the imprimatur of the party.

"It's the Democratic establishment lining up behind the preferred candidate," he said.

Likely aimed at fundraisers and donors, the move could be enough to scare off other potential challengers like Rep. Stephen Lynch or Rep. Michael Capuano, Whalen said.

"It's at least a shot across their bow," he said.

Whalen said the statement was likely part of Markey's strategy in announcing so early.

"It's not a coincidence Kerry made the statement so soon after Markey announced," he said.

The statement may be good news for outgoing Sen. Scott Brown as well, providing him with a "monolithic democratic state party" pick for an opponent, Whalen said.

"If I was Scott Brown, I'd be gleeful," he said.