Washington  - The space shuttle Discovery was nearing the International Space Station for a planned docking later Tuesday.

The Discovery is to deliver the fourth and final solar panel to the International Space Station on a construction mission that will enable it to double the size of its crew to six astronauts. Three spacewalks are planned to install the solar panels and conduct other construction projects.

The mission will also deliver Japanese astronaut Koichi Wakata, who is slated to join the permanent crew on the orbiting space station.

Washington  - US President Barack Obama nominated Daniel Rooney, the owner of American football champion Pittsburgh Steelers, as the next ambassador to Ireland on Tuesday, Saint Patrick's Day.

Rooney, 76, has played an important role in the Irish-American community.

Rooney, through charitable groups, supported the Irish peace process and co-founded the American Ireland Fund in 1976, which has raised more than 300 million dollars for peace and education programmes in Ireland.

Baghdad  - The Iraqi government led by Prime Minister Nuri al-Maliki Tuesday repeated its call for the execution of three officials from the former regime of Saddam Hussein for genocide, as a dispute over sentencing continued.

Former ministers Ali Hassan al-Majid and Sultan Hashem and Hussein Rashid Mohammed, a former army chief, were sentenced to death in 2007 for their part in the so-called Anfal campaign against Kurdish civilians and militia in 1988.

Washinton - A group of scientists who worked on the Phoenix Mars lander last year say they have found evidence of liquid salt water on the red planet.

An analysis of photographs from the lander that explored Mars for six months shows drops of what could be salty, liquid water on the legs of the lander.

They believe the droplets were kicked up from just below the planet's surface when Phoenix landed in May and say they grew and merged over time much as water particles would do.

Washington  - US President Barack Obama praised the people of Northern Ireland for rejecting violence and standing up for peace against "those who would seek to destroy it."

Obama spoke at a White House ceremony Tuesday to celebrate Saint Patrick's Day with the traditional visit by the Irish prime minister, Brian Cowen.

The meeting comes as authorities in Northern Ireland continue to investigate the murders of two British soldiers and a policeman by an extremist splinter group associated with the now disbanded Irish Republican Army (IRA).