US Secretary of State Antony Blinken arrived in Algeria on Wednesday and held talks with President Abdelmajid Tebboune and Foreign Minister Ramtane Lamamra.
Mr Blinken's visit is the last stop of a regional tour that also took him to Israel, the West Bank and Morocco.
The top US diplomat said at a press conference in the Algerian capital, Algiers, that at each stop security issues, urgent regional and global challenges and ways to create more opportunities for people were discussed.
He lauded the relationship between the two countries and hailed Algeria's efforts as "critical to improving regional security and stability".
He said on Wednesday that Washington backs UN efforts in the Sahara region.
"The United States supports the work of the UN personal envoy of the secretary general, Staffan de Mistura, in leading the political process ... to promote a peaceful and prosperous future for the people living in there," Mr Blinken told a press conference at the US embassy in Algiers, after talks with Algerian leaders.
The Sahara region is a former Spanish colony under Morocco's control, where tensions with the separatist militant Polisario Front have simmered since the 1970s.
Algeria has long hosted and supported the Polisario Front, which seeks full independence for the territory and has demanded a UN-supervised self-determination referendum as provided for in a 1991 ceasefire deal.
On the issue of human rights, Mr Blinken said he reaffirmed to the Algerian president and the prime minister the importance of concrete progress on human rights including the freedom of religion and the freedom of expression, especially political speech.
He added that he also discussed with the Algerian officials ways to "build on robust trade and investment ties".
"American companies here are hoping to diversify Algeria's economy," he said.
Mr Blinken said he had an "excellent meeting" with Sheikh Mohamed bin Zayed, Crown Prince of Abu Dhabi and Deputy Supreme Commander of the UAE Armed Forces, in neighbouring Morocco on Tuesday.
Mr Blinken told reporters that energy was not a focus of the talks and said he assured Sheikh Mohamed of Washington's support against attacks from the Iran-aligned Houthis in Yemen and welcomed the UAE's support for a truce in Yemen that could lead to a ceasefire.
