Seeking to bolster national team football amid the rampant success of club competitions, UEFA's 54 member countries voted to create the Nations League on Thursday.
The competition will replace most continental friendlies — long unpopular with club coaches — when it kicks off in September 2018.
UEFA boosted the new event by guaranteeing it would feed into qualifying for the 2020 European Championship. It could later be incorporated into European qualifying for the 2022 World Cup.
"This is a very important decision for the future of football at the level of national teams," UEFA President Michel Platini said after the unanimous vote at their annual congress.
Platini had pledged to raise the status and commercial value of friendlies. It has struggled against competition from popular and lucrative European domestic leagues and UEFA's own Champions League.
The European Club Association representing more than 200 clubs said it "has taken note" of the announcement which could fuel club vs. country tensions.
It requires them to release their players for extra competitive fixtures.
"The European clubs do not oppose such a project, as the number of international matches in the calendar remains unchanged," said the ECA, which campaigned to remove the February and August dates once set aside for friendlies. "Once more details concerning the competition format are available, ECA will analyze the possible impact on club football."
Platini acknowledged that friendlies "really don't interest anybody."
"Neither the audience at large, neither the journalists nor the players," he said later at a news conference.
The Nations League format is yet to be finalized, although it foresees 54 teams ranked in four divisions playing from September to November 2018.
The 12 highest-ranked teams would play in four three-team groups in Division A. Those group winners would advance to a "final four" tournament in June 2019. Teams could be promoted or relegated through the divisions.
All 54 teams would still play in traditional Euro 2020 qualifying groups from March-November 2019.
The qualifying playoffs for Euro 2020 would then be scheduled in March 2020. That lineup would be decided by Nations League results of teams which did not qualify directly for the tournament.
Platini confirmed that each of the four divisions, including the lowest-ranked, should send one team to Euro 2020. That would offer teams such as the Faeroe Islands, Gibraltar or San Marino a chance to debut at a major event.
Euro 2020 will be played across Europe in 13 different host cities which will be picked in September.
UEFA will likely try to include the subsequent Nations League in the European qualifying program for the 2022 World Cup in Qatar. FIFA is considering redrawing football's international calendar to play that tournament in November-December 2022 to avoid the desert heat of Qatar's summer.
"We have to see when the World Cup will take place and we can discuss this further," UEFA secretary general Gianni Infantino said.
In voting on Thursday, members also agreed to give UEFA central control of marketing rights to "all national team matches also for the period 2018-2022."
Europe's top clubs, who often hold out their best players from friendlies, will have concerns about extra matches and injury risks for their players.
The international group of players' unions, FIFPro, predicted added stress on elite players who are often rested for friendlies or do not play the full 90 minutes.
"That will change when there is more at stake," FIFPro director Tijs Tummers said in a statement.
Infantino countered that the Nations League would limit travel as national teams would have fewer chances to travel globally for friendlies.
"It is rather good news they will have their players back earlier and not exhausted from intercontinental trips," he told a news conference.