Aug 15 (Reuters) - NATO is maintaining its diplomatic presence in Kabul and helping to keep the city"s airport running, the military alliance said on Sunday as Taliban insurgents entered the Afghan capital. "NATO is helping keep Kabul airport open to facilitate and coordinate evacuations," NATO Secretary-General Jens Stoltenberg said on Twitter. Stoltenberg said he had discussed the rapidly evolving situation in Afghanistan with Britain"s Prime Minister Boris Johnson and the foreign ministers of Canada, Denmark and the Netherlands. Taliban insurgents entered Kabul on Sunday and said they expected to take power within days. read more A NATO official told Reuters the alliance was maintaining its diplomatic presence in Kabul. The official did not respond to questions on whether NATO planned to hold a crisis meeting to discuss the situation in Afghanistan. "NATO is constantly assessing developments in Afghanistan," the official said, adding that the security of the alliance"s personnel was paramount and NATO would continue to adjust as necessary. After almost two decades, NATO this summer completed military operations in Afghanistan and withdrew most troops from the country. The alliance still operates a diplomatic representation in Kabul. A NATO spokesperson on Friday declined to provide details on the representation, citing security concerns, in response to a Reuters request. Headquartered in Brussels, NATO also serves as a forum to coordinate national measures in Afghanistan, such as the evacuation of citizens that was discussed by NATO ambassadors on Friday.