.
Everton are fuming after losing the midfielder, 20, following a contract wrangle.
But Toon boss Hughton said: "We're fortunate to have signed Dan and we're delighted to have him. We're 100 per cent sure we've done everything right."
Hughton also confirmed defender Steven Taylor will be out for three months as he recovers from surgery on a dislocated shoulder.
Injury-prone Taylor, 24, has not played since a knee op in January and is not due back in action until the end of October.
Hughton added: "It's a big blow for us and Steven. We've lost a very good player in a vital position.
"To continue his injury jinx into this season is a major disappointment."
Blackpool, Newcastle and West Brom are keen on the £1million Turk striker, 22.
The ex-England defender, 35, blamed Toon's training kit for making him look tubby.
Campbell, signed on a free from Arsenal this summer, was slated by Magpies fans over an unflattering training ground photograph.
Supporters labelled him the 'Hog on the Tyne' and fear he will be a fat lot of good.
But Campbell said: "I'm a naturally big guy. I can't rush my conditioning, otherwise trying too much too quickly could result in injuries.
"It's pathetic. I'd been training for three days, just three days! I am three weeks behind everyone in pre-season. Don't they know I have just got married and been on honeymoon?
"I accept the picture wasn't flattering and I do need to catch up on my level of fitness.
"But the training kit was not very flattering and showed up all sorts."
After signing a one-year deal worth £30,000 a week, Campbell hopes to make his first Toon appearance in Saturday's friendly at Rangers.
And boss Chris Hughton has refused to rule him out of the trip to Manchester United to open the season on August 16.
But the former Spurs star is not so confident.
He said: "The season starts in just two weeks and I really need three to four weeks to get back to peak fitness.
"My message to all the knockers is I am knuckling down and want to play with a great club. Then you can judge me."
Hatem Ben Arfa
Marseille's French international attacking midfielder Hatem Ben Arfa is set to move to Premier League side Newcastle after agreement was reached between the clubs with a view to a one-year paying loan, club sources told AFP on Monday.
The two clubs have agreed a loan deal for a season worth 1.2 million euros with the option to buy.
Newcastle bosses will now begin discussions with the player and his representatives over the personal details of his contract.
The 23-year-old - capped seven times - had been targeted by German club Hoffenheim and Russian outfit Rubin Kazan, but the Franco-Tunisian player preferred to try his luck in the Premier League.
It will be his third club in three years after Lyon - where he won four league titles - and Marseille, who won the French championship last season.
Boss Chris Hughton wants the winger to bolster his side for Toon's first season back in the Premier League.
But the French giants are unwilling to sell and a season-long loan deal appears unlikely.
Marseille club president Jean-Claude Dassier said: "Hatem is part of our squad and will remain so.
"There is no serious and solid offer from Newcastle at the moment."
The Frenchman, 23, nicknamed the Wizard, kicked up a stink after being told he could not leave.
A source said: "Marseille were playing games after saying he could go. He is desperate to play in the Premier League."
Premier League new boys Newcastle are keen to sign the 23-year-old but the French giants insist he is going nowhere.
Ben Arfa is furious with his club's stance and has revealed he has no intention of training next week.
The French international said: "I will not return to Marseille's training ground.
"It's over. I am ready to not play this season. I have my pride, my dignity. I am not a stop-gap.
"Over time, people will see that I was right. Just because we are paid does not mean we are slaves."
The Algerian, 23, who joins in a £1.3million deal, played every minute of his country's three World Cup games this summer.
He also hit the headlines as one of four Algerian stars injured when the Desert Foxes' coach was stoned by Egyptian fans last November.
The 24-year-old has been transfer-listed with the two sides well apart on the financial aspects of the deal.
A spokesman for the Magpies said: "We can confirm that Steven Taylor is on the transfer list."
Taylor's current terms expire at the end of the season when he would be able to leave the club on a free transfer.
As a result, Newcastle have reluctantly decided they may have to cash in on him now.
However, a statement released on behalf of Taylor and his agent Paul Stretford revealed that the player, who was stunned by the club's move, is keen to resolve the situation.
The statement read: "Figures released to the media do not accurately reflect the position of either Steven or his agent.
"Both remain happy to continue negotiations over a new and extended Newcastle United contract.
"Steven was disappointed and surprised to hear through third parties that the club had decided to transfer list him.
"He has always given 100 per cent to the club and will continue to do so given the opportunity."
He said: "To be given a chance to compete against some fantastic sides for a team like Fulham is something I've always dreamed of doing."
Halliche has picked up 20 caps since his debut against Senegal in May 2008 but has spent most of his two-year spell at Benfica out on loan.
His arrival will help plug the gap left in defence by Philippe Senderos, who has been ruled out for six months with an Achilles injury.
Cottagers boss Mark Hughes has already signed £5m Belgian striker Moussa Dembele.
The Tyneside club claim the defender, out of contract next summer, has refused owner Mike Ashley's offer of a four-year deal worth £40,000 a week as he holds out for upwards of £65,000.
The Toon are desperate to keep the local lad. But they have been angered by Taylor and agent Paul Stretford's stance and reluctantly decided to get rid.
Ashley hopes to net at least £5million for the 24-year-old centre-half.
A Toon source said: "Mike believes he has made Steven a very good offer but there has to come a time when enough is enough.
"The way the club is being run now, the days of paying players massive wages are over. It's not the way it works now."
However, a spokesman for Taylor insisted: "Figures released to the media do not accurately reflect the position of either Steven or his agent.
"Both remain happy to continue negotiations over a new and extended contract.
"Steven was disappointed and surprised to hear through third parties that the club had decided to transfer list him."
Boss Chris Hughton wants the Guinea centre-back, 25, as a replacement for Steven Taylor, who was transfer-listed by Toon yesterday.
Cash-strapped Hull are happy to get Zayatte off their £39.3m wage bill.
Keane, 30, is a favourite of the ex-Spurs No 2 and White Hart Lane sources were last night claiming the club were finally ready to let the Irishman go.
The source said: "Spurs would hope for at least £6million and it will be no surprise if the deal was done before deadline day."
And Hughton is set to tie up one striker deal this morning with Hatem Ben Arfa expected at St James' Park to thrash out terms over a year-long loan from Marseille.
The Magpies will have an option to buy the France winger, 23, for around £6million next summer.
Marseille president Jean-Claude Dassier said: "They offered to raise the price for the option to buy if Hatem plays 25 matches."
The Toon are also in talks with Manchester City over a loan switch for Belgian defender Dedryck Boyata, 19.
Boyata has made three appearances for City prior to this season.