Liverpool's owners FSG have said that "no offers for Philippe Coutinho will be considered" following interest from Barcelona in the midfielder.
Sources told ESPN FC on Wednesday that Liverpool had rejected a second bid from Barca worth up to €100 million.
The source said that Coutinho will not be sold and that Liverpool consider the matter closed, and the club's owners have now backed that stance up in a statement.
"We wish to offer clarity as regards our position on a possible transfer of Philippe Coutinho," a statement from Liverpool owners FSG read.
"The club's definitive stance is that no offers for Philippe will be considered and he will remain a member of Liverpool Football Club when the summer window closes."
Liverpool manager Jurgen Klopp also said on Thursday that the club had no plans to let Coutinho leave.
"Liverpool is not a club that has to sell players. That is set in stone," he told Sky Deutschland. "So what they pay in the end doesn't matter.
"From a financial standpoint, there is no price limit to let him go. No price at which we are ready to give in.
"Our goal is to have the best possible team. So we want to keep our guys and add new ones. That is our plan."
Barcelona's follow-up bid came after the Merseyside club first rejected a £72m offer for the Brazil international last month. The Spanish club have plenty to spend after selling Neymar to Paris Saint-Germain for a world-record transfer fee of €222m.
Liverpool legend Steven Gerrard said earlier this week that Coutinho will have to create "war" if he is to leave Liverpool for Barcelona.
Coutinho signed a five-year contract at Anfield in January, with Liverpool ensuring that no release clause was inserted.