The hard-line stance signaled even deeper trouble for the U.S. as it tries to restart Israeli-Palestinian peace talks, which broke down more than a year ago.
Netanyahu left Washington early Thursday after a last-ditch effort to heal the rift over Israel's policies in east Jerusalem appeared to fail. The U.S. wants Israel to stop building Jewish homes in east Jerusalem – the section of the city that the Palestinians want as the capital of a future state.
Netanyahu refuses, saying the entire holy city must remain Israel's capital.
Silvan Shalom, Netanyahu's deputy and sometimes rival in the ruling Likud Party, told Israel Radio on Thursday that he "completely supports" the prime minister, saying that the Jewish people's historical bond to Jerusalem is unbreakable.
"The subject of building in Jerusalem is unconditional and if we blink we will lose everything," Shalom said, warning the government would collapse if Israel backs down.
"The prime minister has a mandate not just from Likud voters or the Jewish people here but from the Jewish people from throughout the generations and therefore in this regard we have no option to accept another decision and no other decision can be made."
While he said the relationship with Washington is critical for Israel, he said "the United States needs to understand that if it is one sided only and all the pressure is on Israel only, then that way doesn't contribute and might cause an opposite effect. The efforts need to be directed to both sides."
Netanyahu's culture and national infrastructure ministers made similar comments in radio interviews Thursday.