WASHINGTON, (AFP) – US President Barack Obama said Thursday it was time for rival Iraqi parties to form a government “without delay,” cranking up US pressure for an end to the political deadlock in Baghdad.

Obama made the comment in an Oval Office meeting with US ambassador to Baghdad Christopher Hill and US troop commander General Ray Odierno, the White House said.

Vice President Joe Biden issued a similar US call meanwhile for an “inclusive” Iraqi government, in telephone conversations with Iraqi Prime Minister Nuri al-Maliki and his arch rival for the leadership Iyad Allawi.

“Following Iraq’s successful democratic election in the spring, the president shared his view that it is time for Iraq’s leaders to exercise their constitutional responsibilities and form a government without delay,” the White House said in a statement.

“The president expressed his regret for the July 22 rocket attack on the international zone, but welcomed General Odierno’s report that security incidents across Iraq remain at the lowest level since the US has kept records. “The president also welcomed General Odierno’s report that we are ahead of schedule in executing our planned drawdown to 50,000 troops by the end of August.”

The United States, which also says it is on course to pull all its troops out of Iraq by the end of 2011, has repeatedly pressured Iraqi leaders to form a new government following inconclusive elections in March.

“The vice president reiterated his call for an inclusive government,” Biden’s office said in a statement about his two telephone calls.

Biden stated that the United States expected “all four winning Iraqi coalitions to play a meaningful role” in forming and running a new government,” the statement said.

In a sign of concern about how long the process is taking, Biden visited Iraq in early July, to urge politicians to put aside personal ambitions and form a government representative of all Iraqis.

But tug-of-war over who will become Iraq’s new prime minister has left efforts to form a government following elections in March deadlocked, and there are fears extremists will use the political vacuum to foment insecurity.

Earlier, three security contractors working for the US government were killed in a rocket attack on Baghdad’s heavily-fortified Green Zone – in the attack mentioned by Obama.

Five other people were killed in incidents in northern Iraq’s main city of Mosul and the former rebel bastion of Fallujah, west of Baghdad.