The unmanned Dragon capsule from the private US firm SpaceX successfully berthed at the International Space Station Sunday on its third trip carrying supplies and equipment to the orbiting lab.

NASA television broadcast live images of the crew inside the ISS as the capsule was installed on the Earth-facing port of the Harmony module, a US-built utility hub, at 1406 GMT.

It said the capsule, which berthed with the help of a long robotic arm, took place 260 miles (418 kilometers) above Brazil.

Hours earlier, the 17.6-meter (57.7-foot) arm reached out and captured the gumdrop-shaped capsule from space at 1114 GMT.

"Capture complete, congratulations to the entire team," said the Japanese station commander, Koichi Wakata, who was in charge of operating the mechanical arm along with American Rick Mastracchio.

"We're excited," a smiling Wakata added.

Astronauts were dressed casually in polo shirts as they carried out the Easter Sunday procedure, whose next steps include pressurizing the vessel between the capsule and ISS.

Once this is completed, the capsule's goodies, including food, new space suits, components to replace those aboard the ISS and equipment for 150 scientific experiments, can be unloaded.

NASA said it expects the hatch will be opened in what will be early Monday morning in the United States.

SpaceX has a $1.6 billion contract with NASA for a series of future supply missions.

This marks the California-based company's third commercial resupply mission and fourth visit to the ISS.

After three delays, a SpaceX Falcon 9 rocket blasted off with the Dragon capsule from Cape Canaveral in Florida on Friday afternoon.

The mission had originally been scheduled for mid-March but did not go ahead because of technical issues.

The Dragon capsule is due to deliver 2.2 tonnes of cargo, including the equipment for 150 scientific experiments.

One of the experiments will be the Vegetable Production System, or Veggie, which would allow the production of salad-type crops to safely feed the astronauts.

Another experiment seeks to determine why an astronaut's immune system weakens in microgravity.

NASA is also sending an experiment system that can more rapidly transmit data using a laser communication system, in a first from space.

In all, SpaceX is due to complete 12 missions for the US space agency.

SpaceX became the first commercial entity to reach the space station with its Dragon cargo ship in May 2012 in a trial run. Owned by Internet entrepreneur Elon Musk, the company's first cargo mission took place in October that year.

The last mission involving a Dragon capsule was completed in March 2013.