Alexis Sanchez Chile
Alexis Sanchez joins Arsenal after spending three years with BarcelonaReuters

Arsenal seem to be making a habit of spending some money in the transfer window, after all. A summer after bringing out that cheque book to sign Mesut Ozil for a club record fee, Arsenal have put their vast resources to good use again, by officially announcing the signing of Chile international Alexis Sanchez from Barcelona.

It became clear quite a while back that Sanchez was the marquee signing that Arsene Wenger was after during this summer transfer window, and the fact that the Gunners beat out the likes of Juventus and Liverpool to the speedy forward's signature will go a long way in reaffirming their intent to be as competitive as possible in the English Premier League and all the other competitions in the coming season.

"Chile international striker Alexis Sanchez has agreed to join Arsenal Football Club on a long-term contract for an undisclosed fee," the club confirmed on their official website.

Arsenal agreed a fee of around £30 million with Barcelona, who were keen to offload the forward as soon as possible in order to raise some cash to complete their signing of Luis Suarez from Liverpool.

The Reds were keen to take Sanchez to Anfield as part of the Suarez deal, but the Chile forward, who had an impressive 2014 FIFA World Cup campaign, made it clear he had his heart set on a move to Arsenal, after Wenger reportedly met the 25-year-old in Brazil.

"As many people have seen during the World Cup this summer, Alexis is a fantastic footballer and we are delighted that he is joining us at Arsenal Football Club," Wenger said.

"Alexis will add power, creativity and much quality to our squad and we are all looking forward to him joining up with us in a few weeks.

"He has consistently produced top-quality performances at the highest level for a number of seasons now and we are all excited to see him integrate into the Arsenal squad. I'm sure all Arsenal supporters will join me in welcoming Alexis to our club."

Sanchez spent three years at Barcelona, scoring 39 goals in 88 appearances, despite never really being first-choice, after making a big-money move from Udinese. The forward has shown his capabilities for scoring the big goals against big teams, something that Arsenal sorely missed last season.

The Chilean's pace and directness will also be a huge boost for Wenger's plans, with Mesut Ozil given yet another option to pick out those magical through balls. Sanchez completed his medical on Thursday after cutting short his holiday in order to sign on the dotted line, with his four-year contract reportedly earning him around £140,000 a week.

"I'm so happy to be joining Arsenal, a club which has a great manager, a fantastic squad of players, huge support around the world and a great stadium in London," Sanchez said. "I'm looking forward to meeting my new team-mates and to be playing for Arsenal in the Premier League and Champions League. I will give my best to Arsenal and want to make all the supporters happy."

Arsenal are also expected to announce the signing of Mathieu Debuchy soon, with the right-back replacing Bacary Sagna, who signed for Manchester City on a free transfer.

Wenger is in the market for a defensive midfielder, with Bayer Leverkusen's Lars Bender, Morgan Schneiderlin of Southampton and Ozil's good friend Sami Khedira on the radar, while the manager will also want to bring in a goalkeeper to act as competition for Wojciech Szczesny after the departure of Lukasz Fabianski to Swansea City.

Loic Remy is another player that could join the Arsenal ranks, with the club reportedly ready to trigger the QPR striker's £8 million release clause.