JACKSON (AP) — Roger Wicker was sworn in Tuesday as Mississippi’s newest senator and it didn’t take long for the Republican to outline some ambitious plans for the state, including hopes of securing another $1 billion in federal Hurricane Katrina aid.

Gov. Haley Barbour, a fellow Republican, appointed Wicker in December to succeed former U.S. Sen. Trent Lott, the GOP’s second highest ranking senator before resigning Dec. 19.

Lott was a shrewd power broker in the Senate who helped deliver millions of federal dollars to Mississippi, especially in the wake of the 2005 storm that decimated the Gulf Coast. Wicker expects the federal funds to keep flowing.

‘‘It’s not unrealistic to think that the Congress will provide another billion dollars, that’s billion with a ’b,’ for additional appropriations involving the coast,’’ Wicker said in a conference call with reporters after the swearing-in ceremony in Washington. ‘‘And this would include environmental cleanup, which I think the federal government has an obligation to do, as well as hazard litigation.’’

Wicker, a 56-year-old Tupelo resident, was sworn by Vice President Dick Cheney as some of Wicker’s friends and family looked on.

He will serve until a state-mandated special election is held. The winner will serve out the remainder of Lott’s term, which runs through 2012.

Barbour set the election date for Nov. 4 to coincide with other regularly scheduled elections. However, Attorney General Jim Hood has challenged the timing in court and the state Supreme Court likely will have the final say. Hood says state law requires that the election be held within 90 days of Lott’s resignation. Wicker plans to run in the special election, but said the timing of it is ‘‘a matter for the lawyers and the judges.’’

In the meantime, Wicker said there are plenty of issues to keep him busy, including the threat of a national economic downturn or recession as well as unfinished business in Mississippi’s long recovery from Katrina. He said federal help is needed to restore the line of barrier islands off the Mississippi coast that act as the state’s first line of defense against storm surges.

‘‘The barrier islands off the coast are our levees down there,’’ he said. ‘‘They need to be replenished and we have a plan to do that but it’s going to take some more money.’’

Mississippi Democratic Party Chairman Wayne Dowdy called Wicker’s concern for the coast disingenuous.

‘‘It’s nice that Roger Wicker is backing issues important to South Mississippi that he has ignored,’’ Dowdy said in a statement. ‘‘But voters also need to consider Wicker’s record of trading pork barrel spending for campaign cash, running up the federal debt and voting against the minimum wage — all well-documented facts.’’

Before being appointed to the Senate, Wicker served in the U.S. House since 1994, being re-elected six times from the 1st District in north Mississippi.

Wicker said the House passed important Katrina-related legislation that he hopes to help push through the Senate that would help protect those who live with the threat of hurricanes.

‘‘We need to end this debate between wind damage and water damage and provide for the public an actuarially sound ability to buy insurance to protect you from a hurricane,’’ Wicker said.

He was referring to the ongoing battle between homeowners who suffered catastrophic damage and insurance companies that refuse to pay claims if the damage was caused by storm surge rather than wind.

Barbour, who often says that the recovery from Katrina is the state’s highest priority, has praised Wicker for his work as a member of the House Appropriations Committee.

Also on the special election ballot for the Senate seat are former U.S. Rep. Ronnie Shows and former Mississippi Gov. Ronnie Musgrove, both Democrats. Candidates will run in the special election without party labels.