GENEVA (Reuters) - The United States could bolster the battle against the Ebola virus in Democratic Republic of Congo by allowing more of its experts to travel to the outbreak zone, a senior World Health Organization (WHO) official said on Friday.

FILE PHOTO: A Congolese health worker administers Ebola vaccine to a child at the Himbi Health Centre in Goma, Democratic Republic of Congo, July 17, 2019. REUTERS/Olivia Acland/File Photo

The virus has killed more than 1,700 people in Congo since the world’s second-worst outbreak was declared almost a year ago and is threatening to spread to the major city of Goma or spill over Congo’s border into Uganda.

Poor security in the affected areas has hampered efforts to contain the outbreak and calls are growing for foreign aid agencies to deploy more staff on the ground.

This month former U.S. Ebola response coordinator Ronald Klain called on the White House to reverse its policy of keeping U.S. Centers for Disease Control (CDC) staff out of outbreak zones, and Britain has said too many countries were using security as an excuse not to send people to the front line.

WHO currently has over 600 staff in the field, with 200,000 person-days spent in the field in total, but emergencies chief Mike Ryan told reporters that many agencies could redouble their efforts and deploy more people in the field.

“It is hard to fight a battle without your best ally at your side,” WHO’s emergencies chief Mike Ryan told reporters, when asked about CDC’s deployment.

“But our colleagues in CDC have provided amazing support, both in Congo, in the surrounding countries, here in Geneva, in our operation centers in backstopping and providing high level technical assistance to the response,” Ryan said.

Healthworkers are hoping to keep the virus bottled up by tracing people who may be at risk and vaccinating them and anyone else they might have infected.

The outbreak remains confined to two provinces of northeastern Congo. Last week the WHO designated it an international emergency, prompted partly by a case in the city of Goma, adjacent to Rwanda, and by a patient who went to a market in Uganda and subsequently died in Congo.

Uganda had three Ebola deaths in June, and if it were not for the recent scare, it would now be declared Ebola-free, having achieved 42 days with no new cases.

Ryan suggested it was premature to sound the all-clear.

“Do we have any indications at the moment of Ebola transmitting in Uganda? No. But is there a continued threat of importation? Obviously, yes.”