US Secretary of Defense Mark Esper has sought to reassure NATO allies that Washington will consult them on any future troop movements, after President Donald Trump surprised partners at the military alliance by announcing the withdrawal of thousands of personnel from Germany.
The Pentagon chief on Friday paid a short in-person visit to NATO headquarters in Brussels, a week after several allied defence ministers expressed concern about the unpredictability of US troop plans in Europe and amid a withdrawal in Afghanistan.
"I welcome that the US is consulting with allies, while making clear that the US commitment to European security remains strong," NATO Secretary-General Jens Stoltenberg said in a joint video statement before holding talks with Esper.
Last week, Trump said he is ordering a significant reduction in troop strength in Germany, from about 34,500 personnel to 25,000.
Members of his party have criticised the move as a gift to Russia and a threat to US national security. Germany is a hub for US operations in the Middle East and Africa.
Trump said this week that the troops could be moved to Poland.'Delinquent' Germany
Germany was not notified of the move, which came after Trump branded its NATO ally "delinquent" for failing to pay enough for its own defence, by not meeting a goal set in 2014 for members to halt budget cuts and move towards spending at least 2 percent of gross domestic product (GDP) on defence by 2024.
Esper reaffirmed that message, saying: "I continue to urge all of our allies to meet their target goal of 2 percent of GDP. We've moved a good distance here in the last few years but there's much, much more we need to do to ensure our collective security."
On Thursday, Secretary of State Mike Pompeo again took aim at Germany.
"We do consider Russia to be a serious threat. Spending 1 percent of your GDP on defence, as Germany does, acknowledges that they may well not take it as serious of a threat as the United States of America takes it. They need to," Pompeo said.
"That doesn't show the resolve that [Russian President] Vladimir Putin needs to see from Germany," he added.
According to NATO figures, Germany has allocated 1.38 percent of the GDP to its defence budget this year.
Berlin aims to hit 1.5 percent by 2024 and insists that this level of spending allows it to meet NATO's defence planning goals.
The US - at about 3.4 percent of its GDP - spends more on defence than all 29 other allies combined.
In a statement after talks with Esper, Stoltenberg underlined that "the US military presence in Europe is important for Europe, and it's also important for North America. Because only by working together can we address the great challenges we face."
On Afghanistan, where NATO has led security efforts since 2003 and recently began to pull troops out in line with a US-brokered peace deal with the Taliban, the statement said the alliance "will continue to adjust its presence" and that this will "be done in close coordination with allies and partners".