US Ambassador Kathleen FitzGibbon arrived in Niger on Saturday, the State Department announced, taking up her post as the United States and partners continue to grapple with the military takeover in that country.

"Ambassador Kathleen FitzGibbon has traveled to Niamey to lead our diplomatic mission in Niger and bolster efforts to help resolve the political crisis at this critical time. As a career senior diplomat with significant experience specializing in West Africa, she is uniquely positioned to lead U.S. government efforts in support of the American community and the preservation of Niger's hard-earned democracy," State Department spokesperson Matthew Miller said in a statement.

FitzGibbon arrived in the capital city of Niamey more than three weeks after members of the presidential guard detained democratically elected President Mohamed Bazoum and his family and declared themselves the new leaders of the country. US officials continue to insist that there is a window to convince the junta leaders to step down and restore democratic rule to the West African nation, which serves as a critical partner to the US in the region.

However, diplomatic efforts -- including a trip to Niger by Acting Deputy Secretary of State Victoria Nuland -- thus far have not yielded any progress, and the prospect of a military intervention by the Economic Community of West African States still looms.

State Department deputy spokesperson Vedant Patel said Wednesday that FitzGibbon, who was confirmed by the Senate in late July after a lengthy wait, "is going there to lead the mission during a critical time and to support the American community and to coordinate on the US Government's efforts."

"Her arrival does not reflect a change in our position, and we continue to advocate for a diplomatic solution that respects the constitutional order in Niger, and for the immediate release of President Bazoum and his family," Patel said. "We remain committed to working with African partners to promote security, stability, and democratic governance in the Sahel, and Ambassador FitzGibbon will be an integral piece of that when she gets to post in Niamey."

It is unclear, however, what sort of diplomatic engagements FitzGibbon will be able to hold amid the state of uncertainty in Niger.

A source told CNN that one of the first things FitzGibbon intends to do is call Bazoum. Secretary of State Antony Blinken has spoken with the detained president numerous times, but Nuland was not permitted to visit him during her trip to Niamey.

Nuland was also not granted a meeting with the self-proclaimed new leader of Niger, General Abdourahmane Tiani, and instead met with the self-proclaimed chief of defense, Gen. Moussa Salaou Barmou, and three colonels supporting him.