Mashaal told Aljazeera on Wednesday that Hamas's decision in March to agree to a ceasefire period with Israel was part of "a campaign of tactics and manoeuvres in order to put the ball back in the Israeli and American court".
Hamas was one of the Palestinian factions that agreed to a ceasefire with Israel, brought about during a meeting in March with Palestinian leader Mahmoud Abbas.
The truce depended on Israel also agreeing to stop all military operations against the Palestinians and to release Palestinian prisoners.
The Cairo deal followed a joint declaration by Abbas and Israeli Prime Minister Ariel Sharon to an end to more than four years of violence during a 8 February summit in Sharm el-Sheikh, Egypt.
Mashaal, who is based in Damascus, Syria, said agreeing to the truce did not mean the group had given up its fight against Israel.
"Our position is clear. We are committed to resistance and will not consent to any dismantling of resistance groups and laying down arms before the occupation leaves our land. This is a constant position on which we will never bargain," he told Aljazeera.
He said the decision to agree to a truce also stemmed from Hamas's desire to give the Palestinian people a rest from the violence of the uprising, and to also "expose Sharon's ruse aimed at sparking Palestinian infighting through the marketing of an illusion of peace after (Palestinian leader Yasser) Arafat's death" late last year.
Mashaal told Aljazeera recent attacks against Israeli targets were not initiated by Hamas, but were a retaliation for "thousands of Israeli violations of the truce agreement", in which he said 35 Palestinians were killed, dozens wounded and more than 500 people were detained.