Lausanne -Swimming's world governing body has made a "strong appeal" to 208 member federations not to boycott events for political reasons.
FINA says its ruling bureau declared it "does not tolerate any form of political motivation to justify the non-participation in our events."
Though FINA did not specify a reason for the statement, it was released just months ahead of the world championships to be held in Russia.
Kazan will host the championships in swimming, diving, open water swimming, synchronised swimming and water polo from 24 July to 9 August.
Since tensions flared between Russia and Ukraine over a year ago, European football body UEFA ruled that teams from the two countries could not be drawn to play each other.
At FINA's 2013 world championships held in Barcelona, Ukraine won five medals - one silver and four bronze - in diving and synchronised swimming.