S President Donald Trump has made his first TV address to the nation from the Oval Office, escalating a stand-off with Congress that has led to an 18-day partial government shutdown.
Mr Trump insisted on funding for his long-promised US-Mexico border wall.
However, he did not declare an emergency that would enable him to bypass the lower house of Congress now controlled by the opposition Democrats.
Democratic leaders accused him of holding the American people hostage.
The Republican president wants $5.7bn (£4.5bn) to build a steel barrier, which would deliver on his signature campaign pledge.
But Democrats – who recently took control of the House of Representatives – are adamantly opposed to giving him the funds.
The ongoing closure of a quarter of federal agencies is the second-longest in history, leaving hundreds of thousands of government workers unpaid.