WASHINGTON, Dec. 2 -- U.S. President Donald Trump touted defense spending increase by members of the North Atlantic Treaty Organization (NATO), after years of pressuring allies with a combination of criticism and threats.

"Since I took office, the number of NATO allies fulfilling their obligations more than DOUBLED," Trump tweeted Monday, shortly after departing for Britain from the White House, adding that the bloc's spending increased by 130 billion U.S. dollars.

According to numbers released by NATO last week, NATO members excluding the United States have spent 43 billion dollars more on spending in 2018 compared with 2016, and the projected differences between the years of 2020, 2022 and 2024 and 2016 will widen to 130 billion, 246 billion and 400 billion dollars respectively.

In a visit to Washington in November, NATO Secretary General Jens Stoltenberg underscored that NATO members are increasing their defense spending, in a gesture seen as an appeasement to Trump.

"By the end of next year, these Allies will have added an additional 100 billion dollars to their defense budgets. That's billions of dollars for new equipment. New investment in the latest technologies," Stoltenberg told an industry forum during his visit, which also included a meeting with Trump in the oval office.

The increased spending came after years of threats and criticisms against European NATO members from Trump, which analysts say handed Trump a symbolic victory but weakened U.S. leadership and the bloc's unity in the long run.

In a shocking remark to the Economist magazine in November, French President Emmanuel Macron said NATO was experiencing "brain death," pointing to the lack of leadership from Washington.

The scathing attack was rebuked by other leaders of NATO members and reportedly annoyed Trump deeply, but Macron has refused to budge on his position.

Trump has shown a cool attitude toward NATO even before he entered the White House, calling the bloc "obsolete" days before his inauguration. He then stopped short of affirming article 5 of the NATO treaty during a visit to NATO headquarters in May 2017, triggering concerns over U.S. commitment for the safety of other NATO members.

Trump cranked up the heat once more during a Brussels summit in 2018, explicitly saying that the United States could "go our own way" if other member countries do not meet the 2-percent GDP threshold for defense spending.

But Trump's critics downplayed his role in getting NATO allies to pay more in defense spending, pointing out that NATO members excluding the United States have been increasing their defense spending since 2014, before Trump assumed the presidency.

According to NATO figures, NATO members excluding the United States spent 250 billion dollars on defense in 2014 and have since been on the climb, expecting to reach 302 billion dollars in 2019.

In a background briefing to the press Friday, a senior administration official said the upcoming London summit will be a "celebratory leaders' meeting," featuring bilateral meetings between Trump and Stoltenberg and Macron respectively.

But an Axios report Monday said European leaders are nervous about Trump's message during the summit, given his record during past NATO summits.

"All I'm hearing is great anxiety about what Trump might do or say," Axios cited former U.S. ambassador to NATO Ivo Daalder as saying.