President Joe Biden on Thursday called for the immediate release of Nigerien President Mohamed Bazoum in a written statement commemorating Niger's Independence Day, saying the US "stands with the people of Niger" as the country faces a "grave challenge to its democracy."

This marks the first time Biden has commented on the situation in Niger since last week's military takeover.

"The Nigerien people have the right to choose their leaders. They have expressed their will through free and fair elections -- and that must be respected," Biden said. "Defending fundamental democratic values, and standing up for constitutional order, justice, and the right of peaceful assembly, are essential to the partnership between Niger and the United States."

"I call for President Bazoum and his family to be immediately released, and for the preservation of Niger's hard-earned democracy," he added.

Biden's statement comes as the US has engaged in intensive diplomatic efforts to restore democratically-elected Bazoum to power.

Secretary of State Antony Blinken spoke by phone Wednesday with Bazoum, who was detained last week, State Department spokesperson Matthew Miller said.

"The United States is dedicated to finding a peaceful resolution that ensures that Niger remains a strong partner in security and development in the region," Miller said.

The US has not formally decided if the situation should be designated as a coup, a move that would require the US to cut foreign and military assistance to the Nigerien government. There is no time requirement for the US to make such a designation.

Amid the tension in the country, the State Department ordered the evacuation of non-emergency personnel and family members from Niger on Wednesday.

"On July 26, President Mohamed Bazoum was placed under house arrest amidst efforts to overthrow the democratically elected government of Niger. Subsequent events have severely limited flight options," the State Department said in an updated travel advisory.

"Given this development, on August 2, 2023, the Department ordered the departure of non-emergency U.S. government employees and eligible family members from Embassy Niamey," it said. "The U.S. Embassy in Niamey has temporarily reduced its personnel, suspended routine services, and is only able to provide emergency assistance to U.S. citizens in Niger."

But the ordered departure does not mean that the US is closing its embassy or evacuating all of its diplomats. Roughly 1,100 US troops in the country were restricted to American military bases earlier this week but are not expected to leave the country at this point, according to US officials.