US President Joe Biden on Wednesday reiterated his country's commitment to not allow Iran to become a nuclear power. In a phone call with Israeli Prime Minister Yair Lapid, Biden "underscored the U.S. commitment to never allow Iran to acquire a nuclear weapon," according to a readout by the White House. Hailing the "unbreakable bonds and friendship" between the two countries, Biden also stressed the importance of "concluding the maritime boundary negotiations between Israel and Lebanon in the coming weeks." The phone call came amid concrete developments in the nuclear deal of major Western powers with Iran, an agreement fiercely opposed by Israel. The US struck a guarded note of optimism Wednesday that it can reach an agreement with Iran on a mutual return to the landmark 2015 nuclear accord. "We still remain hopeful that we can get a reimplementation of the JCPOA," National Security Council spokesman John Kirby told reporters, using the formal acronym for the agreement. “We do believe we're closer now than we have been in recent weeks and months, due in large part to Iran being willing to drop some of their demands that were not related to the deal at all.” "We're cautiously optimistic that things can continue to move in the right direction," he added. The Joint Comprehensive Plan of Action (JCPOA) saw an international inspections regime imposed on Tehran's nuclear program in exchange for relief from biting international sanctions that hobbled Iran's economy.