Former US president and Republican leader in the nomination for the elections, Donald Trump, has once again criticised NATO countries and their contribution to aid Ukraine, demanding they pay more.

"We are into helping Ukraine for more than 100 billion dollars more than NATO. We have nobody that they respect, and they insist on paying far less than we do. 

Wrong, NATO has to equalise, and now. They will do that if properly asked. If not, America first!" Donald Trump said on Truth Social.

Trump claimed that during his presidency, he made NATO "strong" by compelling alliance members to pay more to reach the defence spending target of 2% of GDP. 

He thinks that there has been regression since then.

"When I told the 20 Countries that weren't paying their fair share that they had to pay up, and said without doing that you will not have US Military Protection, the money came rolling in. After so many years of the United States picking up the tab, it was a beautiful sight to see. 

But now, without me there to say you must pay, they are at it again."

Donald Trump has previously recalled how, as president, he demanded fair contributions from other NATO members and threatened to withdraw from the North Atlantic Alliance if re-elected as US president.

During a rally in South Carolina, Trump reminisced about how, during his presidency, he threatened to "encourage Russia" to attack a NATO member that did not fulfil its financial commitments to the Alliance.

Amidst Trump's controversial statements, the US State Department reminded the public of events post 11 September 2001, when NATO came to the defence of the United States.

The former president's words also triggered a sharp reaction from the White House, NATO Secretary-General, and many European capitals.

The President of the European Council, Charles Michel, called Trump's words irresponsible. German Chancellor Olaf Scholz deemed Trump's statements dangerous and suggested they played into Moscow's hands.