Barack Obama will tomorrow announce an end to US combat operations in Iraq, but his televised address from the Oval Office risks being undercut by the failure to form a government in Baghdad, and new casualty figures indicating an escalation in violence.

Obama is to present as a milestone the reduction in US troops in Iraq, from 144,000 when he took office last January to below 50,000. But the Iraqi foreign minister, Hoshyer Zebari, said today it was an "embarrassment" for the US to withdraw without an Iraqi government in place. In spite of US claims that violence is on a downward trend, the Iraq Body Count released figures showing that the death toll for August was 495. A further five were killed today , bringing the toll to 500, which, when taken together with July, marks one of the bloodiest spells since 2008. The remaining 50,000 troops, who will focus mainly on assisting the Iraqi army, are scheduled to pull out by the end of 2011, unless the Iraqi government – assuming one is eventually formed – asks for a few hundred or few thousand to remain.

With US opinion polls showing the president's popularity below 50% and his Democratic party facing a drubbing in November's Congressional elections, Obama badly needs a foreign policy success and the White House, state department and defence department have worked hard in recent months to present a positive narrative of events in Iraq.

In his address Obama will present the reduction of US troops as the fulfilment of a key pledge made during the 2008 White House election in which he promised to end US military operations in Iraq. In a foretaste of his address, Obama insisted today that violence has been on a downward trend. "The trend lines have been steadily declining violence. Even after we left the cities [US troops pulled out last year] what you've seen is lower and lower levels of violence," Obama said in an interview with NBC News. "The Iraqi security forces are functioning, at least as well, if not better, than any of us had anticipated."

When the Iraq Body Count published its figures for July, with a death toll of 535, US forces in Iraq disputed it, suggesting the real figure was 222. Iraq's health ministry said it would release its August death toll on Wednesday, but confirmed that its number was similar to the Iraq Body Count figure.

Zebari, who has been an advocate of a speedy US withdrawal, appears to be having second thoughts with the deadline for the end of combat operations in Iraq imminent. "They [the Obama administration] had also made this part of an election campaign, so for them it is a very important event," Zebari told the Guardian. "It is the fulfilment of that election pledge. But it is embarrassing for them to withdraw and still we don't have a government in place, because all the achievements, all the sacrifices that have been made, could be in jeopardy. It is embarrassing for us also."

Obama faces a challenge in striking the right tone with his speech: he will seek to avoid the kind of premature triumphalism that saw President George Bush stand under a banner announcing "Mission Accomplished" only weeks after the 2003 invasion, but he will also try to take take credit for making good on an election pledge. One of the leading military analysts in the US, Anthony Cordesman, of the Centre for Strategic and International Studies, said: "President Obama is walking a tightrope where he has to balance the fact that US troops are down from a peak of over 140,000 to under 50,000, against the reality that the average number of violent incidents in Iraq is not that much lower than in Afghanistan, and it will be years before the insurgency is over."

He added: "He has to talk about strategic partnership without knowing how the new Iraqi government will view the US, and its ties to [the Shia leader Moqtada al-Sadr] or Iran. He has to talk about US withdrawal knowing that once a new Iraqi government is formed it could ask for US forces to stay longer or provide combat support – or demand US forces leave more quickly."

For better or worse? Iraqis on US legacy



When the Americans entered the country in 2003, we were pleased to get rid of one tyrant, but the Americans brought hundreds of tyrants instead of one. Everything we dreamed of became a lie – a mirage in a desert. All we got was oppression, killing and unemployment. The Americans have left behind a weak country, with weak officials whom Iran is playing as a hand of cards for their own interests. We are heading towards a dark future and we are going to be divided by sects. They planted the seeds of division and we are exhausted by lack of electricity and clean water.

Sheikh Nouri al-Diyaa tribal leader from Falluja, central Iraq

Any country that has been under occupation will face suffering and ruin. We hope the situation in Iraq will be improved by the American withdrawal. It will not be done quickly – we don't have a magic wand to correct all the miserable things that were left behind. But at least now we feel comfortable and are pleased that the US troops are leaving our country and respecting the security pact. We thought we would at least get some development from an occupation as miserable as it was, but we have seen a deterioration in all areas of life in Sadr City.

Sheikh Hussam al-Sayedi from Sadr City, Baghdad

"Toppling Saddam was a huge achievement but the next chapter has taken a very long time. We suffered from many mistakes of the Americans and were treated mercilessly by the militias. We thought that Bush's announcement in 2003 would quickly turn into a reconstruction effort, but it became an occupation, with people behaving increasingly worse towards us. The people that gave the American troops flowers soon began to hate them. They seemed to spend more money on prisons than anything else. They are leaving us with a weak army and government. But at least I can say that things are much better in Basra here. The progress during the past two years has been amazing and we have far more freedoms than we did under Saddam."

Hashim Laebbei civil servant in Basra, southern Iraq

"The reality is that the occupiers destroyed the country, then left. For seven years they could not control things, so them pulling out won't make a difference. They left us without a professional army or security forces and they have surrendered our country to Iran. There are so many negatives about the occupation. There is one positive though; at least we can leave Iraq."

Sheikh Ammar Meshari from Diyyala, eastern Iraq

"There were some benefits of the occupation, such as new salaries and more opportunities. But look at the downside, perhaps millions dead, orphans and handicapped. The situation here is very vague and is likely to get much worse. It is not a long road back from where we are now to more assassinations and civil war."

Ahlam Omar unemployed, west Baghdad

"When the Americans came we were very happy, first to get rid of Saddam Hussein and also because the Kurds are the best allies in Iraq. We immediately thought of investment and stabilisation. And it's fair to say that we have benefited more than any other area in Iraq. Life has improved, the economy is very good, the oil sector is doing well and we have huge projects under way in health and tourism."

Dashti Abdulallah Mustafa journalist from Erbil, Kurdish region