Mike Pence greets troops in a hangar at Bagram Air Field in Afghanistan

US Vice President Mike Pence arrived on an unannounced pre-Christmas visit to Afghanistan Thursday, becoming the most senior Trump administration official to visit troops fighting a 17-year-old conflict that has largely receded from US public view.Flying secretly through the day and night on a standard unmarked US Air Force C-17, Pence corkscrewed into Bagram Airforce Base, where he thanked some of the roughly 15,000 US personnel still hoping to turn the tide of America's longest-ever war.The superpower's vexed campaign against Al Qaeda and the Taliban -- born from the rubble of the 9/11 attacks on New York and Washington, receives ever-less public attention in the United States these days.Pence's visit is designed to shift the spotlight back on personnel and their mission, however briefly, before Americans turn their focus to turkey lunches, festive cheer and contentious domestic politics.Pence's visit also included a perilous helicopter dash from Bagram into the heart of the capital Kabul to meet President Ashraf Ghani and Chief Executive Abdullah Abdullah, both of whom the United States is counting on to help rebuild this war-shattered country."We've been on a long road together" he said. "We've both sacrificed much."But, he added "we are here to see this through."Pence's visit comes four months after Trump unveiled a new strategy for Afghanistan.With typical certitude, the 45th commander-in-chief promised a nation "weary of war without victory" a more ruthless campaign, and one without Obama-era exit deadlines or niceties."We are not nation-building again. We are killing terrorists," Trump said in unveiling the strategy at Fort Myer, Virginia in August. "In the end, we will win."But, the fact that Pence's visit took place in secrecy and under cover of winter darkness is a stark reminder of the difficult security situation even around Kabul and even after a war effort worth more than half a trillion dollars.His visit from Bagram to central Kabul was in doubt until the last moment, when a White House official said he countermanded a decision that the weather was not clear enough to travel.Even then, Pence's helicopter flight took place in near total darkness, hovering low and fast and with a heavy phalanx of secret service and special forces.The White House official said the decision was made "out of respect. To meet with Ghani and Abdullah".The White House had looked at the possibility of bringing the pair out to Bagram, but that plan was dropped given the political sensitivities about the symbolism of an Afghan leader traveling to meet a US vice president in their own country.The Trump administration, like Barack Obama's before has put enormous hope in Ghani, who is seen by the White House as more competent and less corrupt than his predecessor Hamid Karzai.But his three-year-old "national unity" government appears to be faltering and parliamentary elections have been repeatedly postponed.Pence was expected to press Ghani and Abdullah to go ahead with that vote and with presidential elections that are scheduled soon after.

Pence had been expected to visit Egypt and Israel this week, a trip that was delayed amid a crunch vote on tax cuts and deadly protests at Trump's decision to recognize Jerusalem as Israel's capital.