Declaring a strong desire to deliver New Jersey voters an elected senator in short order, Gov. Chris Christie (R) announced Tuesday that he is setting a special election to fill the late-Sen. Frank Lautenberg's seat for October, with a primary slated for August.

"I want to have an elected senator as soon as possible," Christie told reporters at a news conference. He announced the primary would be held on Aug. 13, while the special general election will follow on Oct. 16.

"I firmly believe that the decision that needs to be made in Washington are too great to be determined by an appointee for a period of 18 months," the governor said.

Christie's decision spares him having to worry about a top Democratic Senate recruit appearing on the ballot on Nov. 5, something that could boost the hopes of state Sen. Barbara Buono (D), Christie's underdog opponent in the governor's race.

But the governor also opens himself up to criticism from Democrats over the price tag of holding a separate election, in the month before a normal election is slated, no less. Holding special primary and general elections could cost nearly $24 million, according to an estimate from the New Jersey Office of Legislative Services.

Christie sought to preemptively assuage such concerns, saying Tuesday that "the state will be responsible for all the costs of this election."

Meantime, Christie is expected appoint an interim senator, but he said Tuesday he has not made that decision yet. The governor said he will appoint the person he deems to be the best qualified, regardless of whether they opt to run in the special election or simply serve as a placeholder until that time.

"There is one bucket of people, and those people are the people best qualified to serve," Christie said.

Christie didn't put a timetable on his decision-making process, but said it would not be long.

"I don't dawdle," he said.

Lautenberg died Monday, triggering a vacancy that has been the source of considerable debate. Murky state law suggested the timing of the election to replace Lautenberg could either come in 2013 or 2014.

Democrats have been calling for Christie to set the election for Nov. 5, the same day the governor faces reelection. “It needs to be happen in November,” state Senate President Stephen Sweeney (D) said Monday, threatening legal action if Christie doesn’t comply.

Christie is also likely to face grumbling from the Republicans who'd hoped for a 2014 election and a GOP appointee who could be afforded the time to build a record in the Senate and a base of support ahead of facing voters in the deep blue state next year.

What's more, whoever the Republican Senate candidate is won't have the benefit of appearing on the same ballot as the widely popular Christie on Nov. 5.

Newark Mayor Cory Booker (D) has been actively exploring a Senate bid for months and has been widely viewed as the frontrunner for the seat. But a contested primary in 2013 could be a problem for Booker. Unlike in 2014, members of the state's congressional delegation would be freed to run without giving up their seats. Rep. Frank Pallone (D) has been considering a run for months, too. And others could be prompted to give the race a look.

Senate Majority Leader Harry Reid (D-Nev.) said he was pleased with the timeline Christie set up.

"I'm happy with what he's done," Reid told reporters regarding Christie's decision to hold an election in October, saying in part that the decision to move ahead quickly avoids legal challenges to his decision. "I think that the people who serve in the Senate, if the election laws in the state call for it, should be determined by the electorate."

At his weekly lunch stakeout, Senate Minority Leader Mitch McConnell (R-Ky.) sais he didn't second-guess Christie.

“I’m sure the governor exercised whatever options he has in the best interest of state and I don’t question” his decision, McConnell said.

Whoever wins the special election will have to go back into campaign mode almost immediately because a 2014 election for a full term will be on the horizon.

-- Ed O'Keefe contributed 

Updated at 3:09 p.m.