China's Tiangong space station is expected to welcome its first foreign visitor — a Pakistani astronaut who will likely become the first from the Islamic republic to fly to outer space, according to a heavyweight cooperation agreement.

The agreement, signed by the China Manned Space Agency and Pakistan's Space and Upper Atmosphere Research Commission at a ceremony in Islamabad on Friday, covers the bilateral efforts to select and train Pakistani astronauts and then send some of them to China's Tiangong space station, which has been in orbit for nearly four years.

Witnessed by Pakistani Prime Minister Shehbaz Sharif, the signing marks the first time for China to help a foreign nation to select and train astronauts, and also the first time for the Tiangong space station to welcome a non-Chinese inhabitant, the China Manned Space Agency said in a news release.

The Chinese agency said the two sides will use about one year to complete the selection process before sending the Pakistani candidates to China to receive comprehensive and systematic training. Details of when the selection process would begin have not yet been disclosed.

After the Pakistani trainees become ready, one of them will accompany Chinese astronauts to the Tiangong space station and spend a short-term stay inside the colossal spacecraft, currently orbiting Earth at about 400 kilometers above ground, the agency noted.

To date, the highest altitude any Pakistani has ever reached is about 87.4 km, by a female polar adventurer and artist Namira Salim during a 55-minute suborbital travel arranged by American aerospace company Virgin Galactic on Oct 6, 2023.

It is common knowledge that the Karman line, an altitude of 100 km above sea level, is the start of outer space and the threshold for orbital flight.

The signing of the cooperation agreement has created fresh opportunities and set a model for more developing countries to engage in international manned space collaboration. It is expected to inspire nations worldwide to join hands in exploring the mysteries of the universe and collectively forge a new chapter in advancing shared interests for the benefit of all humanity, according to the release.

Since the launch of the Tiangong's first component in April 2021, Chinese space officials have floated the idea about picking and sending foreigners to the space station.

Key project leaders such as Yang Liwei, the first Chinese in space and now a deputy chief planner of the country's manned spaceflights, and Lin Xiqiang, deputy head of the China Manned Space Agency, have said several times that China is open to international cooperation on its space station, including flights jointly crewed with other nations.

Chen Shanguang, another senior official in China's manned space program, said in February 2023 that "multiple countries have told China that they hope to send their astronauts to the Tiangong station".

Tiangong is one of the largest and most advanced structures ever deployed in Earth's orbit and is the only operating space station independently built by a single nation.

The Chinese outpost has three permanent parts — a core module and two science capsules — and is regularly connected to several visiting crew and cargo spaceships. It now weighs more than 100 tons and is expected to function for at least 10 years.

So far, eight crews have been sent to man the space station, including the incumbent Shenzhou XIX team, which arrived at the outpost in late October and is scheduled to return in late April or early May.

In August 2017, Samantha Cristoforetti of Italy and Matthias Maurer of Germany, both from the European Space Agency, participated in a sea survival exercise, which was organized by the Astronaut Center of China, in waters off the coastal city of Yantai, Shandong province.

They were the first foreign astronauts to take part in training in China.