BRUSSELS: A senior US defense official will brief NATO countries Thursday on Washington's review of its forces in Europe, officials said, in the face of fears over an American pullback from the continent.

US Defense Under Secretary Elbridge Colby will meet ambassadors from NATO countries at the headquarters of the 32-country alliance in Brussels.

"The United States is consulting with allies as part of its force posture review," a NATO official said Wednesday.

Washington launched a six-month review in July as it presses European countries to take principal responsibility for the conventional defense of their continent.

The move was announced by Pentagon chief Pete Hegseth amid US anger at the response of European nations to the war with Iran, including restrictions on US forces using their bases at the start of the conflict.

As part of the process, the United States is quizzing countries over their defense spending and approach to American forces using bases, European diplomats said.

"We need to send a united European message on Thursday to show how we are stepping up together as a whole," said one diplomat. "It is not a beauty contest."

US President Donald Trump's administration has long pressured Europe to spend more on defense as it signals it wants to step back to focus on other challenges such as China.

The Pentagon has already told allies it is reducing the number of assets it makes available for NATO's defense plans.

Washington also said in May it would withdraw 5,000 troops from Germany, but Trump later said he was sending the same number to neighboring Poland.

European countries are massively ramping up military budgets, agreeing in 2025 to Trump's demand to devote 5% of GDP to security-related spending by 2035.

Elbridge Colby

Top US official to meet NATO allies over force review