Ananova:

The top United States and British diplomats have told Iraqi leaders that they cannot afford to "leave a political vacuum" and must work quickly to form a new unified government.

The surprise visit by US Secretary of State Condoleezza Rice and Foreign Secretary Jack Straw highlighted the allies' growing impatience with the Iraqis' failure to set up a governing coalition nearly four months after elections.

Rice told reporters that she and Straw conveyed the same message to each of the leaders they saw: that each must do his own job in resolving the political stalemate and do it quickly.

"Whatever role that is, it's time to play it because the Iraqi people are losing patience," Rice said.

"What is more, your international allies want to see this get done because you can't continue to leave a political vacuum."

One of those leaders, Foreign Minister Hoshyar Zebari, said Rice and Straw made clear "there is a sense of urgency to form this new Iraqi national unity government" and that "there is a sense of impatience back in Washington and London about the delay".

En route to the Iraqi capital from England, Rice said she and Straw were going urge that negotiations should be concluded.

Straw said the choice of leaders was up to Iraqis alone.

But neither he nor Rice disguised the blunt nature of their mission.

Straw said: "There is significant international concern about the time the formation of this government is taking, and therefore we believe and we will be urging the Iraqi leaders we see to press ahead more quickly."