Facebook has topped one billion users, but the past few months have not been easy for the social media company.

CEO Mark Zuckerberg says that the company is going through a bit of a rough patch following its rocky initial public offering.

Zuckerberg updated his Facebook status on Thursday to announce that the social networking site has more than one billion active users each month. He thanked users and said that he is committed to making Facebook better.

The Menlo Park, California-based company has had a difficult time of late.

There were trading glitches the day it went public in May and concerns since then about its revenue potential. It's also facing lawsuits from disgruntled shareholders.

"We're in a tough cycle now and that doesn't help morale, but people are focused on what they're building," Zuckerberg said in a 'Today' show interview Thursday.

Last month, Zuckerberg gave his first interview since Facebook's shaky IPO, and since that time he's been working hard to boost confidence among investors and the public.

Zuckerberg told Matt Lauer during the 'Today' interview that Facebook's future is about mobile, an area it's been criticised for not capitalising on quickly enough.

The 28-year-old executive also continued to reassure that he is the right person to lead Facebook, as some on Wall Street have questioned whether he has the ability to lead a large public company.

"I take this responsibility very seriously," he said.

Facebook Inc's stock gained 45 cents, or 2.1 per cent, to US$22.28 in premarket trading. The shares closed at US$21.83 on Wednesday, off 43 per cent from its US$38 IPO price.

- AP