Hawaii Gov. Neil Abercrombie (D) selected Lt. Gov. Brian Schatz on Wednesday to fill the vacancy created by the death last week of veteran U.S. Sen. Daniel K. Inouye (D).

With the “fiscal cliff” five days away and critical decisions facing the Senate, the White House said Schatz would fly to Washington on Wednesday evening with President Obama. Schatz said he would be in place to be sworn in Thursday.

Abercrombie chose Schatz, 40, a former state Democratic Party chairman and state lawmaker, over U.S. Rep. Colleen W. Hanabusa (D), whom Inouye had indicated shortly before his death would be his preference to replace him.

“No one and nothing is pre­ordained,” Abercrombie told reporters in Hono­lulu. He said Inouye’s views were taken into account but so were those of grass-roots activists and his own analysis of what was best for the state.

He said Schatz, a native of Michigan, was best positioned to help Hawaii begin to rebuild its congressional seniority.

He called Schatz “intelligent, forceful, insightful, committed.”

Schatz will be joined in the Senate next month by Rep. Mazie K. Hirono (D), who was elected in November to replace retiring Sen. Daniel K. Akaka (D).

The pair of newcomers will replace one of the nation’s most stable lawmaking teams: A modest World War II hero, Inouye had represented the Aloha State in the Senate since 1963, becoming president pro tempore of the chamber and chairman of the powerful Appropriations Committee. Akaka has served in the Senate since 1980.

Schatz will hold the job for two years until Hawaii voters choose a replacement to fill out the final two years of Inouye’s term.

Schatz, who will be one of the Senate’s youngest members, told reporters that he is planning to stand for election in 2014 to complete Inouye’s term and then to run for reelection in 2016.

“No one can fill Senator Daniel K. Inouye’s shoes — but together, all of us, we can try to walk in his footsteps,” Schatz said, indicating he would focus on retaining federal funding for the state and addressing climate change.

The selection of Schatz was something of a surprise, given Inouye’s wishes and the esteem with which he is held in the state. But Abercrombie is close to Schatz and indicated that he was hesitant to choose Hanabusa and force a new special election to fill her House seat.

Jennifer Sabas, Inouye’s chief of staff, indicated in a statement that Hanabusa’s selection was ­Inouye’s “final wish.”

“While we are very disappointed that it was not honored, it was the governor’s decision to make. We wish Brian Schatz the best of luck,” she said.

Rising Democratic star Tulsi Gabbard, 31, an Iraq war veteran and former Hono­lulu City Council member who was elected to the House in November, had some strong supporters nationally, including Newark Mayor Cory Booker, who endorsed her for the Senate seat via Twitter.

The appointment of Schatz came at a particularly critical time, with Democratic leaders anticipating a potentially close vote in the coming days on a tax plan designed to avert the most serious economic impacts of the year-end fiscal cliff.

In the absence of a broad, bipartisan deficit-reduction package, Obama has called on Congress to at least pass a bill to extend tax breaks for the middle class and potentially forestall automatic budget cuts set to hit in January.

Democrats hope that Republicans will agree to forgo a filibuster and allow an up-or-down vote on a temporary fix, requiring only a bare majority to pass. If the GOP requires a 60-vote threshold for the bill, as has increasingly become standard in the Senate, Democrats hope that a handful of Republicans would join Democrats in supporting the measure and send it to the House.

Either way, Democrats will need every vote they can muster if the legislation is brought to the floor. A bill passed by the Senate in July to extend tax rates first enacted under President George W. Bush for those making less than $250,000 a year was adopted by a narrow 51 to 48 margin.

All Republicans opposed the measure, along with Sens. James Webb (D-Va.) and Joseph I. Lieberman (I-Conn.).

With tax hikes set to hit virtually every American in a matter of days, a similar measure could pick up additional support this time around. But the possibility of a squeaker vote led Senate Majority Leader Harry M. Reid (D-Nev.) to take the unusual step of urging Abercrombie to fill the Hawaii seat quickly.

“It is critically important to ensure that the people of Hawaii are fully represented in the pivotal decisions the Senate will be making before the end of the year,” Reid said in a statement Saturday.

Hawaii law required that Abercrombie choose a replacement from a list of three finalists selected by the state Democratic Party.

The party’s central committee met Wednesday — several days earlier than had been planned before Reid’s request for speed — to hear two-minute speeches from most of the 14 candidates who had formally asked the party to consider them for the role.