Samaria Regional Council Head Yossi Dagan responded to Israeli Prime Minister Binyamin Netanyahu's urging to wait on the law to annex Ma'ale Adumim and halt the building freeze in Judea and Samaria.
Dagan is currently in Washington, D.C. and holding meetings with Trump officials.
"We will not allow ourselves to miss this historical opportunity. The Obama government has left and in its place we have an administration which supports Jewish communities in Judea and Samaria," Dagan said. "There was never a more supportive government than Trump's for Judea and Samaria. Netanyahu is trying to be more leftwing than Trump."
Dagan also said he would hold a meeting with the Likud party if Netanyahu failed to keep his promises.
"We will stand as a wall opposing the Prime Minister's attempts to let this historic opportunity to build in Judea and Samaria slip through our fingers."
Immediately after US President Donald Trump's inauguration on Friday, Dagan told Arutz Sheva that the ball "is in Netanyahu's court."
"I respect the Prime Minister. This is an historic moment, but if someone thinks the new president is going to be more of a Zionist than the Israeli Prime Minister, he is wrong.
"The Israeli government should have continued building in Judea and Samaria during the Obama administration as well. They should not have allowed a building freeze.
"There is no doubt this is an historic moment, but there is a chance Trump will condemn building in Judea and Samaria, despite all his support for Israel," Dagan warned.