The World Cup kicks off with host nation Qatar facing Ecuador on Sunday, as the month-long football showpiece finally gets under way after a tortuous 12-year build-up dogged by off-field controversies.

Foreign government officials, VIPs and celebrities will be in the crowd as the first World Cup staged in the Arab world opens at the Bedouin-tent-inspired Al Bayt Stadium in Al Khor, 50 kilometres outside of Doha.

The venue is one of an array of brand new stadiums built for the tournament, which has cost Qatar an estimated $200 billion.

The World Cup 2022 opening match will begin at 5pm Malta time, following a 30-minute opening ceremony that will be headlined by South Korean K-pop star Jung Kook.

Organisers say the opening ceremony will reflect themes of "humanity, respect and inclusion".

Qatar will be hoping to impress home fans with a win: no host nation has ever lost its opening game in World Cup history. 

It is the first time that the World Cup is being held at this time of the year, with FIFA having shifted away from its traditional June slot due to the blazing temperatures Qatar sees during that time. 

While temperatures will be nowhere near the 50C it can reach in summer, November temperatures still reach 32C during the day and 22C in the evening. All the World Cup stadiums are air-conditioned.

In part due to the unusual scheduling, this will be the shortest World Cup since Argentina 1978, lasting just 29 days. 

To fit the competition into that schedule, there will be several days with four (rather than the standard three) games during the group stages, and there will be no break between the end of the group stages and start of the knockout phase. 

Group stage games will take place at 11am, 2pm, 5pm and 8pm Malta time.

An event dogged by controversy

World Cup organisers hope the start of the football will quell the controversies that have overshadowed preparations for the tournament ever since Qatar was named as host nation in a shock FIFA vote in 2010.

Qatar's treatment of migrant workers and the Gulf state's human rights record have dominated the pre-tournament headlines.

On Saturday, FIFA president Gianni Infantino went on the offensive in an aggressive rebuttal of the opprobrium aimed at the event, arguing that much of the criticism was unfair.

"This moral lesson-giving -- one-sided -- is just hypocrisy," Infantino said.

"I don't want to give you any lessons of life, but what is going on here is profoundly, profoundly unjust."

FIFA president Gianni Infantino accused western countries of hypocrisy during a press conference on Saturday. Photo: AFP

Controversies look certain to rumble on into the tournament even after the action starts.

Several European nations taking part -- including England, Germany and Denmark -- have said their players will wear rainbow-coloured "OneLove" armbands in a gesture of solidarity with the LGBTQ community. Homosexuality is illegal in Qatar.

The move raises the prospect of disciplinary action from FIFA, who on Saturday revealed plans to make their own alternative armbands available to teams.

Infantino insisted that all World Cup visitors would be welcome regardless of sexual orientation.

"I've been speaking about this topic with the highest leadership," he said. "They can confirm that I can confirm that everyone is welcome."

Benzema blow, Brazil arrive

All 32 teams competing at the World Cup have now arrived, with five-time champions Brazil the last to touch down in Doha late on Saturday.

Defending champions France suffered another injury hammer blow early Sunday after confirmation that star striker and Ballon D'Or winner Karim Benzema had been forced out of the tournament with injury.

The Real Madrid star limped out of a training session at the French camp on Saturday evening with a left thigh injury.

The French Federation later confirmed in a statement that the 34-year-old would require "a recovery period of three weeks" and would play no part in the competition.

"I am extremely sad for Karim, for whom this World Cup was a major objective," said France coach Didier Deschamps.

"Despite this new blow for the France team I have full faith in my squad. We will do all we can to rise to the huge challenge that awaits us."

Benzema's withdrawal comes with France already battling the injury absence of star midfielders Paul Pogba and N'Golo Kante.

Brazil, who have been installed as favourites by many bookmakers, were greeted by hundreds of fans from South Asia and South America.