UEFA President Aleksander Čeferin and South American Football Confederation (CONMEBOL) counterpart Alejandro Domínguez opened the office.

The London office will represent CONMEBOL and UEFA in common projects, including competitions, it is stated.

"CONMEBOL and UEFA have decided to take their cooperation to a higher strategic level," Domínguez, who was earlier this month re-elected as CONMEBOL President until 2027, said.

"We are the two continents with the most notable tradition and prestige in the most popular sport on the planet. 

"On the pitch we are loyal rivals, but the comprehension that football is a powerful force for tolerant, peaceful and pluralistic societies, unites us."

The joint office was promised in a September extension of a UEFA-CONMEBOL cooperation agreement.

That agreement facilitated their respective men's champions, Italy and Argentina, facing off in the Finalissima at London's Wembley Stadium on June 1.

More collaboration on tournaments is expected, including the possibility of South American teams joining the UEFA Nations League.

"Building a fruitful and lasting relationship such as ours came easy as we share the same love and passion for football," Čeferin added.

"This shared office is the symbolic next step in the right direction for UEFA and CONMEBOL. 

"It will help us work jointly to develop football across our confederations and beyond."

UEFA and CONMEBOL have both publicly opposed a proposal to play the FIFA World Cup every two years.

Momentum behind the idea appeals to have stalled, and FIFA President Gianni Infantino sought to distance himself and the global governing body from the proposal at last month's FIFA Congress.

"Let me be very clear that FIFA has not proposed a biennial World Cup," Infantino said.

The proposal was tabled by the Saudi Arabian Football Federation (SAFF), which has aligned itself closely with Infantino, and the FIFA leader has insisted the organisation was only studying the feasibility of the plan as he seeks to re-shape the narrative surrounding the idea.

Infantino met with Saudi Arabia's Crown Prince Mohammed bin Salman bin Abdulaziz Al Saud as well as the SAFF President just last month.

The FIFA leader is also on record as saying a World Cup every two years would still retain its "magic".

FIFA held a global summit on the controversial proposal in December, which has been driven in part by celebrated managers Jill Ellis and Arsène Wenger.

Wenger is FIFA's chief of global development, while Ellis heads the FIFA Technical Advisory Group.

Wenger says the existing men's calendar "doesn’t work anymore and is outdated", while Ellis has claimed a Women's World Cup every two years would be capable of "elevating" the women's game at large.