The company is also planning to set up two regional operations centres focused on election integrity in Dublin and Singapore, to help support its efforts to combat fake news.
Speaking alongside Mariya Gabriel, commissioner for digital economy and society, Sir Julian said that tools created to tackle disinformation needed to be made available across all European Union member states and not a select few.
Clegg's announcement came on the same weekend The Guardian accused Facebook of crippling the political advertising monitoring features their transparency project relies upon.
Clegg said these tools will also cover so-called issue ads "which don't explicitly back one candidate or political party but which focus on highly politicised topics like immigration".
The US tech giant was also the centre of FBI investigation over Russia's alleged meddling in the US election of Trump and intervention in votes across Europe.
"We want Facebook to be a universal service".
"We're up against smart and well-funded adversaries who are adapting and changing their tactics, just as we are getting better at preventing abuse".
Facebook's recently-appointed head of global affairs Nick Clegg told a news conference today that the company will require those wanting to run political and issue ads to be authorised.
"Our work around elections is never finished", said Katie Harbath, director of Global Politics and Government Outreach. We believe that anyone should be able to connect to anyone else.
Barely had the furore raised by the proposed unification of the hitherto independent platforms died down, investigative reporters and activists have accused Facebook of blocking third-party ad transparency tools.
The former United Kingdom deputy Prime Minister, who joined Facebook last October, was speaking after the company fights to retain credibility after a year which saw the service under siege after series of scandals where political organisations had misused the platform to sway election results.
Speaking about the structure of the teams reviewing electoral integrity, Clegg said: "This effort will boost our rapid response effort to fight misinformation bringing together dozens of experts from threat intelligence, data science engineering, research, community operations and legal".
The new tools are similar to those adopted for the USA mid-term elections, Clegg said, with all political ads stored in a publicly searchable library for up to seven years. "The library will include information on the range of the ads' budget, number of people they reached and demographics of who saw the ad, including age, gender and location", Samidh Chakrabarti, Director of Product Management, Civic Engagement at Facebook, said in the blog post.
The company will launch the same political ad system for elections in India, Ukraine and Israel in the coming months before it's expanded globally in June.
In a statement given to ProPublica Facebook spokesperson, Beth Gautier said: "We regularly improve the ways we prevent unauthorized access by third parties like web browser plugins to keep people's information safe".