LONDON, Dec. 2 (CGTN) -- NATO leaders meet this week in London to mark the 70th anniversary of the Alliance.

It comes as the transatlantic Alliance faces mounting pressure for change, with some even questioning what its mission should be.

Among them will be U.S. President Donald Trump, who has been fiercely critical of the organization.

CGTN's Toby Muse reports on Trump's plans for the gathering.

U.S. President Donald Trump is expected to meet one-on-one with the leaders of France and Germany during this week's NATO Summit in London.

Trump has a rocky relationship with the Alliance, which is made up of 29 member states. He once called it obsolete.

Trump has long demanded nations spend more on defense, and has claimed credit for recent increases.

The White House says it expects that by 2024, 18 countries will be paying two percent of their budgets towards defense.

Germany has pledged it will match U.S. NATO contributions beginning in 2021.

NATO Secretary General Jens Stoltenberg says defense spending by European members and Canada increased by 4.6 percent this year.

"When leaders met in Brussels last year, they decided to develop national plans," Stoltenberg said. "Now nations have submitted their updated plans to NATO and we see the results. Based on these plans, I can announce that the accumulated increase in defense spending by the end of 2024 will be 400 billion U.S. dollars.”

NATO was created at the beginning of the Cold War with the idea of protecting the West against the Soviet Union. Since the Soviet Union crumbled nearly three decades ago, NATO's reason for being has been less than clear. The U.S. is reportedly pushing for a NATO role in countering China's growing influence.

French President Emmanuel Macron is defending his recent comments, describing NATO as "brain dead.”

"Perhaps it was necessary to have a 'wake-up call', to use the English expression," Macron said. "I said it, I am happy I did so, and I welcome the fact that everyone now considers that the priority is to reflect on our strategic goals and objectives.”

Macron questioned whom the organization should consider an enemy , saying he didn't think it should be Russia or China but instead 'terrorism'. The French president also criticized member nation Turkey's recent military offensive in Northern Syria against Kurdish populations. This enraged Ankara.

Further complicating NATO's agenda is Turkey's decision to buy a Russian anti-missile system.

Russia is calling on NATO to declare a moratorium on deployment of short and intermediate-range nuclear missiles in Europe, since a treaty that banned them ended in August. NATO members have not announced a response.

Can the world's most important military alliance find unity? This week may provide the answer.