In a meeting with the EU foreign policy chief Javier Solana, Israeli Defense Minister Amir Peretz said renewed rocket attacks on the country from Gaza were serious and called for international solidarity on the boycott, Ynetnews reported.
"I call on you today to announce that so long the escalation continue all intentions to transfer funds to Hamas and to the unity government be stopped," Peretz told Solana.
Japan and Norway indicated willingness to break the boycott that began a year ago January when Hamas won a parliamentary majority.
Hamas is considered by many western countries to be a terrorist organization for its use of violence and refusal to recognize Israel's sovereignty.
"As a man of peace I tell you, you have to warn the international community that all the goodwill it expressed toward the unity government in the Palestinian Authority has to stop," Peretz said.
There was no immediate response reported from Solana.