LONDON — Gianni Infantino, the president of FIFA, is pressing forward with a plan for two new global tournaments that could reshape soccer’s international calendar, putting it on the agenda for a meeting of the sport’s leaders this week. But one of the organization’s most powerful stakeholders is not happy about it, and is threatening to walk out of the gathering in protest.

The proposal, a $25 billion plan for a revamped Club World Cup and a new national-team competition, is fiercely opposed by members of UEFA, European soccer’s governing body.

The plan, from an investment group led by the Japanese conglomerate SoftBank, was introduced earlier this year by FIFA, which oversees global soccer. The new Club World Cup would be a 24-team championship for club teams, with half of the participants drawn from Europe. The second tournament would be a global league of national teams, and would supplant UEFA’s version of a similar competition for European countries, the brand-new Nations League. It would be played under a different format from the quadrennial World Cup.

The proposal has been delayed since the spring, when Infantino introduced it, but FIFA added it to the agenda for its FIFA Council meeting on Friday in Kigali, Rwanda.