* NATO books first increase in defence spending vs GDP since 2009
* European allies at 1.47 percent, still below 2-pct goal
* Trump steps up pressure on Europe to spend more
By Gabriela Baczynska
BRUSSELS, March 13 (Reuters) - Defence spending by European NATO states inched up in 2016 compared to the previous year, data by the military alliance showed on Monday, but still remained below the threshold the new U.S. President Donald Trump said was crucial to achieve.
Trump made NATO states in Europe nervous when he criticised the alliance as "obsolete" during election campaign and then went on to suggest he could make U.S. commitment to their security conditional on them meeting the alliance's target of defence spending at two percent of their economic output.
Trump has since reaffirmed support for the security alliance but insisted Europeans must "pay their fair share." His aides have said Trump wants to see progress on that by the end of this year and that Washington could otherwise "moderate" its support.
NATO said the U.S. defence spending last year stood at 3.61 percent of its Gross Domestic Product, compared to 3.58 percent in 2015. That compares to 1.47 percent for NATO's European allies last year and 1.44 percent the year before.
NATO's overall figure for 2016 stood at 2.43 percent versus 2.40 percent in 2015. (Editing by Toby Chopra)