Washington - The United States will maintain its large military presence in Niger to assist local forces despite the deaths of four American soldiers in an ambush, the Pentagon's top officer said on Monday.Nearly three weeks after jihadists attacked a joint US-Niger patrol in a sensitive border area, General Joseph Dunford, Chairperson of the Joint Chiefs of Staff, said the US is firmly committed to supporting Nigerien forces in counter-insurgency operations.With some 800 US forces deployed in the country, "our intent is to continue operations there," Dunford told a news conference.The October 4 clash, the deadliest US combat incident since President Donald Trump took office in January, has shocked many Americans unaware of the military presence in the African country, the largest US deployment on the continent.The four troops died on a reconnaissance patrol on the Niger-Mali border directly north of Niamey. Dunford said five Nigerien solders were killed, and another two Americans wounded.The 12 American and 30 Nigerien soldiers on the mission were attacked by about 50 fighters Dunford characterized as locals associated with the Islamic State group. Questions have been raised over why it took hours before backup support reached the patrol, and why one US soldier's body was left behind and only recovered the following day.'Very complex situation'Dunford said the October 3-4 mission was originally approved based on an intelligence assessment that they were "unlikely" to come into conflict with any local forces.The unit went to a village near the border and was attacked as they returned to their base to the south.Dunford said that, based on what investigators know so far, the patrol did not call for support until one hour after first being attacked, suggesting perhaps they believed they could handle the situation.A surveillance drone was sent to the location quickly after they did call for support, and two French Mirage jets arrived overhead an hour later.But Dunford gave no details of what took place on the ground, and said he did not know, for example, why the French jets did not drop bombs."This is a very complex situation that they found themselves in," he noted."When they didn't ask for support for that first hour, my judgement would be that that unit thought they could handle the situation without additional support."The incident has drawn calls from Congress for an investigation into the US presence in Niger.A US special operations raid on Mogadishu in 1993 became a massive firefight leaving 19 US soldiers dead and resulted eventually in the pullback of US forces from Somalia.The 800 deployed in Niger are part of around 6 000 US forces on the continent, mostly there to train local partners."We mitigate the risk to the US forces with specific guidance that we will only accompany those (local) forces when the prospects of enemy contact is unlikely."Dunford said the Niger clash reflects the globalization of the fight against IS, even as it loses ground in Syria and Iraq.