The introduction of frontal cockpit protection has been postponed until 2018 after the Strategy Group voted against the use of the halo for 2017.
Formula 1 has been seeking to increase head protection for next season and evaluated two potential routes, with the halo favoured over the aeroscreen.
The halo was trialled by both Ferrari and Red Bull amid suggestions of a debut in 2017, but the Strategy Group did not approve its implementation when it met on Thursday.
The Strategy Group comprises FIA President Jean Todt, Bernie Ecclestone and representatives from Mercedes, Ferrari, Red Bull, Williams, Force India and McLaren.
“It was decided that owing to the relatively short timeframe until the commencement of the 2017 Formula One season it would be prudent to use the remainder of this year and early next year to further evaluate the full potential of all options before final confirmation,” read a statement issued by the FIA.
“This will include undertaking multiple on-track tests of the ‘Halo’ system in practice sessions during the rest of this season and during the first part of the 2017 season.
“While the Halo is currently the preferred option, as it provides the broadest solution to date, the consensus among the Strategy Group was that another year of development could result in an even more complete solution.
“[The] Halo remains a strong option for introduction in 2018.”
Additionally, following drama at recent races, the regulations regarding radio communication have been relaxed with immediate effect.
The FIA issued a clampdown at the start of 2016 in order to place more control back to the drivers, but both Nico Rosberg and Jenson Button fell foul of the restrictions in Britain and Hungary respectively.
Button criticised the FIA, amid claims that information was provided to him on safety grounds, and the rules have now been relaxed ahead of this weekend's German Grand Prix.
“At the request of the Teams and Commercial Rights Holder, the FIA has agreed to adopt a more liberal approach to the interpretation of Article 27.1 (that a driver must drive the car “alone and unaided”),” continued the statement.
“With the exception of the period between the start of the formation lap and the start of the race, there will be no limitations on messages teams send to their drivers either by radio or pit board.
“This approach is aimed at providing improved content for fans and spectators, as teams will now be required to provide the Commercial Rights Holder with unrestricted access to their radio messages at all times that their cars are out of the garage.”