Certainly not - no need to pay any extra or have a phone call - they are just irritating pop ups on the site.
I did ask if you had met the friend in person.
The Reason I ask this is because someone is being misled and I cannot tell if it is you , your friend, or both of you.
Whilst the sum involved is impossibly large for you and I in terms of International finance it is negligible.
If there were such funds which needed to be transferred then there would be no need for clearance from anybody at all - not the Uk Tax Office; not our Government (Our Minister of Finance is the Chancellor of the Exchequer who deals with Policy not individual transfers however large) and certainly not the IMF who have no control over the banks at all.
However all of those "requirements" are common language for a Scammer - it is called "advanced fee fraud" and you can read about it here
I am so very very sorry - but you and your friend have been scammed - there is no money waiting for you and I fear that any fees you have paid to date are lost.
Please ask if you need further details