FIFA threatened to suspend Switzerland from world soccer on Saturday if its national association does not discipline litigious club FC Sion within one month.

If the suspension took effect, Swiss champion FC Basel would be prevented from playing Bayern Munich in the Champions League round of 16. The first leg is scheduled Feb. 22 in Basel.

Basel advanced from its Champions League group ahead of Manchester United, which would logically be reinstated by UEFA.

Switzerland's Football Association has a further incentive to meet FIFA's demand - it is scheduled to host Lionel Messi and Argentina in a Feb. 29 exhibition in Bern.

Swiss soccer leaders, including Basel vice president Bernhard Heusler, met Saturday to consider the FIFA ultimatum forcing them to forfeit most of Sion's results this season by Jan. 13.

''We are disappointed. But, in any case, we will do everything necessary to resolve the situation,'' Swiss FA President Peter Gillieron said at a news conference.

Swiss officials will seek a meeting with FIFA lawyers in Zurich next week to clarify what soccer's world governing requires from them.

Sion has breached soccer's rules in a legal saga since 2009 when FIFA imposed a one-year transfer ban for breaking transfer regulations in the signing of goalkeeper Essam El-Hadary.

On Saturday, FIFA criticized ''the attitude of the club repeatedly trying to circumvent this decision in a legally abusive manner,'' in a statement issued after a meeting of its executive committee in Tokyo.

Sion's determination to fight world soccer and legal authorities led it to launch a series of civil court actions against UEFA, which expelled it from the Europa League in September for fielding players that were signed during the transfer ban.

FIFA and UEFA were backed on Thursday by the Court of Arbitration for Sport, which upheld UEFA's right to kick Sion out of the competition based on FIFA's transfer sanction.

Sion refused to accept defeat, insisting it would challenge the decision at Switzerland's supreme court, including on the grounds that CAS was not truly independent.

FIFA stepped up the fight Saturday by ordering the Swiss FA to enforce a ban on registering six Sion players signed in the offseason during the transfer embargo.

''As a consequence, all matches in which the relevant players participated shall be declared forfeit or three points shall be deducted respectively,'' FIFA said. ''Should this deadline not be respected, the Swiss FA will be automatically suspended from Jan. 14, 2012 onwards.''

Under the terms of a FIFA suspension, a country's national and club teams, referees and officials are prohibited from taking part in international matches and meetings, or receive FIFA funding.