After holding on to dwindling hope for days, Sen. Mark Begich on Monday conceded he had lost his U.S. Senate race to Republican Dan Sullivan.

With the concession coming nearly two weeks after the Nov. 4 general election and with few votes left to count, the statement was largely a formality.

The Associated Press called the race nearly a week ago. Soon after, Sullivan attended orientation meetings in D.C. to prepare to take office and voted for Republican leaders in the new Senate majority that takes power in January.

Through it all, Begich refused to back down, drawing heat from critics although his campaign believed key areas of the state might give him a last-minute surge to put him in the lead.

Begich chipped away at Sullivan's lead. On Monday afternoon, the Division of Elections issued new numbers, showing Begich had trimmed what last week had been a roughly 8,000 vote lead to 6,211 votes or to 2.25 percent.

But with more than 279,000 votes counted in the race, few outstanding ballots are expected to arrive. Begich said he called Sullivan on Monday and urged him to work in a bipartisan manner in the Senate.

Sullivan issued his own statement about the congratulatory phone call. Sullivan said he thanked Begich for his service and the two men agreed a smooth transition was important.

"The responsibility of representing and serving Alaskans comes first. I look forward to doing the job that Alaskans elected me to do, and to begin the process of turning our country around and building a brighter future for Alaska," Sullivan said.

In his release, Begich said his campaign was fueled by thousands of Alaska donors and volunteers. He said he refused to cater to a "partisan script crafted by Outside power brokers and billionaires who want to buy power in Washington."

The race was the most expensive in Alaska history, with more than $50 million spent.

"During this campaign, I put my record of delivering for Alaska front and center, and it's why this election was one of the closest races in the country despite over 10 million dollars of attacks from Outside groups and their partisan narrative," he said. "These accomplishments are not red or blue results, they're Alaska results, and the final margin of this election and the clear support I received from independent voters affirms that."

A former Anchorage mayor, Begich knocked off powerful Republican Sen. Ted Stevens in 2008 after Stevens was convicted of federal corruption charges that were later invalidated. Popular among Alaska Native voters, Begich won the state's remote Western and Arctic districts by a large margin. He said he also won 10 of 16 Anchorage districts.

Begich said one of his top accomplishments in office was creating an opportunity for veterans to receive federally supported health care at local health clinics and hospitals without traveling to Veterans Health Administration facilities.

He said he was proud to have opened "the National Petroleum Reserve-Alaska to development, to move forward Arctic oil exploration, and to protect Alaska's postal service."

He added that "saving the F-16s in Fairbanks, protecting missile defense at Fort Greely, and securing two new squadrons of F-35s for Eielson Air Force Base will spur the largest economic investment in Interior Alaska since the construction of TAPS [the trans-Alaska oil pipeline]."

Some have rumored that Begich will take on Republican Sen. Lisa Murkowski in 2016. Begich said he'll keep involved in Alaska.

"As a born and raised Alaskan, I will always be involved in my community, and the results of an election have never diminished my desire or passion to achieve these goals," he said, referring to expanded economic opportunity, legal equality for Alaskans, and prosperous rural communities.