Ahead of Lieberman's visit to Europe, European Union foreign ministers are expected to condemn assassinations and the use of fake passports on Monday, a move designed to censure Israel over the killing of a Hamas commander in Dubai.
Diplomatic sources said the ministers, meeting in Brussels, may not mention Israel by name but their statement was intended to show disapproval at the assassination last month by a team of assassins.
Dubai authorities say the assassins used forged British, Irish, French and German passports and were sent by Israel. Israel has declined to confirm or deny this.
"It will be quite a strong statement... It will make reference to 'extra-judicial killing' and the fact that these passports were used," one of the sources said.
"It doesn't matter if (the statement) doesn't mention Israel, the message will be clear. How many countries can it be referring to?"
The statement is being drafted by France, Germany, Ireland and Britain and will then be put to the rest of the 27 EU foreign ministers for approval, the sources said.
Spanish Foreign Minister Miguel Angel Moratinos said the use of fake passports in the killing of Hamas commander Mahmoud al-Mabhouh in a Dubai hotel on January 19 was an issue of concern for all EU member states.
"We're extremely concerned that a passport, which is a very rigorous and legal document, can be used in a different manner and for a different purpose," he told reporters in Brussels.
"We're going to discuss it and I hope we will issue a statement expressing our concern."
He added he will ask Israeli Foreign Minister Avigdor Lieberman about the affair in the margin of an EU foreign ministers meeting Monday.
Maintaining its policy of ambiguity on sensitive issues such as assassinations, Israel has refused to confirm or deny involvement in Mabhouh's death or the allegations that passports were falsified.
Dubai police say they believe Israeli agents carried out the assassination and have released the identities of 11 people travelling on passports from Britain, Ireland, France and Germany who they say were involved.
Several of those people have denied any role or ever having visited Dubai, leading investigators to suggest the Israel's overseas spy agency Mossad copied the passports and amended them to allow the assassins to enter the Emirate under false identities and carry out the assassination.
Reuters and the Associated Press contributed to this report