Sony said this week that it has sold over 7 million PlayStation 4 videogame consoles in just over four months.

The number includes consoles sold up to April 6, according to Reuters. The company has sold double the amount of consoles compared to the first four months that the PS3 was on sale.

Sony added that it's "struggling" to keep up with demands for the videogame console, the Japanese company said in a statement this week.

"Although we are still facing difficulties keeping up with the strong demand worldwide, we remain steadfast in our commitment to meet the needs of our customers," Andrew House, president and group chief executive officer of Sony Computer Entertainment, said in the statement, according to Reuters.

Sony sold 3.5 million PlayStation 3 units between its launch in November 2006 and the end of March 2007, a Sony spokeswoman said to Reuters.

The $399 console went on sale back on November 29 in the United States, Western Europe and Latin America.

It also went on sale around the same time that rival Microsoft Corp's Xbox One was released in the same locations.

Microsoft has not released updated sales for its Xbox One this month, but the company confirmed it topped 3 million units sold as of the end of 2013.

To increase sales, Microsoft recently started offering a $450 bundle pack that included the game "Titanfall" for free with every Xbox One purchase.

Retail and digital PlayStation 4 software sales reached 20.5 million copies globally by April 13, Sony said, according to Reuters.

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