Masri was responding to comments made by Prime Minister Ariel Sharon, who said that Israel would "make every effort" not to help the Palestinian Authority hold elections if Hamas took part in them.
Masri also said that Hamas's participation in the elections would not spell the end for its war on Israelis.
He added that Hamas was a large and powerful movement, and that no party could ignore it.
"Sharon's words only make us stronger," he said. "We reject this despicable interference by Sharon, and no one will tell us what to do. These things only strengthen our determination and our devotion to our rights," said Masri.
He added: "Sharon's strategy is to split the Palestinian street, but this won't affect our nation which understands that these things were not said out of concern for Palestinian interests. These comments will only make us stronger among our people. We are determined to take part in the elections out of a will to build a new political life, and to build what the Israeli occupation destroyed."
Not giving up on "resistance"
The Hamas spokesman also emphasized that "under no circumstances would we give up on the resistance option, which is our strategic choice."
"Our people know that this strategy of resistance is what brought us the Israeli withdrawal from Gaza, after long years of useless negotiations."
While meeting foreign journalists in New York, Sharon said that if Hamas were to take part in the elections, "We would make every effort not to help them (the Palestinian Authority). I don't think they can hold elections without our help."