By Trevor Hunnicutt

(Reuters) -The United States and Mongolia will sign an "Open Skies" civil aviation agreement, Vice President Kamala Harris and Mongolian Prime Minister L. Oyun-Erdene said on Wednesday at the start of discussions focused on Russia, China and economic development.

Their meeting in Washington on Wednesday comes as the Biden administration works to ease tensions with strategic competitor China and as its relations with Russia show no sign of thawing as the Ukraine war grinds on.

Harris underscored the administration's commitment to strengthening ties with Mongolia and other nations in the Indo-Pacific, with a big focus on combating the climate crisis, upholding democracies and human rights, and addressing threats to the international rules-based order.

"The American people have a profound stake in the future of the Indo-Pacific," Harris said, noting that she and President Joe Biden had each traveled there three times since taking office. "It is in our vital interest to promote an Indo-Pacific region that is open, interconnected, prosperous, secure and resilient."

Surrounded by Russia in the north and China in the south, Mongolia has cultivated allies, such as Japan, South Korea and the United States, in a diplomatic strategy aimed at reinforcing its political independence, but its economy has continued to rely heavily on its two giant neighbors.

Washington has Open Skies civil aviation agreements with more than 130 countries. They grant airlines from both countries the right to operate in each other's countries, liberalize airline regulation and impose safety and security standards.

The Open Skies deal between the U.S. and Mongolia will build on a memorandum of understanding for an air transport agreement between the nations that was agreed in January.

Mongolia's national carrier MIAT Mongolian Airlines flies to Europe and Asia, but not the United States at present. Although passenger demand may not merit non-stop flights between Mongolian capital Ulaanbaatar and the U.S., the Open Skies deal would also provide easier options for cargo flights between the nations.

The new deal with Mongolia comes alongside new cultural exchange initiatives, as well as English-language training in Mongolia.

Each deal is meant to give the landlocked Asian country a Washington-backed alternative for economic development, where corruption has long deterred foreign investment.

Resource-rich Mongolia has extensive deposits of rare earth minerals and copper, which are critical materials in short supply as Biden looks to electrify the domestic auto market.

Oyun-Erdene, who studied in the United States, said the two countries would also sign agreements to deepen cooperation in outer space and strengthen their economic cooperation, with an eye to expanding trade.

He said direct flights between the two countries would begin in the second quarter of 2024, offering a "great opportunity" to promote trade, tourism, business and investment.

"I hope that history will record my visit this week as the start of a new chapter in our friendship and the strategic partnership," he said.

Mongolia has been in talks with Tesla Chief Executive Elon Musk over possible investment and cooperation in the electric vehicle sector. Musk's SpaceX has also been authorized to operate as an internet provider in the country.

Oyun-Erdene said Mongolia would also sign a landmark digital cooperation agreement with Alphabet's Google this week, but gave no details.

(Reporting by Trevor Hunnicutt in Birmingham, Alabama and Andrea Shalal; Editing by Jamie Freed and Jonathan Oatis)