Donald Trump is considering reducing intelligence sharing with NATO allies, which rely on the US for the type of information that has helped Ukraine in its war with Russia, according to foreign officials familiar with the plans.

Three European officials and a senior NATO official anonymously told Politico that Trump advisors informed allied countries that diminished intelligence sharing was part of a larger plan to reduce US support and cooperation with the 32-nation alliance.

The sources said they only discovered such plans when speaking with Trump's advisors about larger plans to diminish the United States' involvement in NATO amid concerns of Trump undermining the alliance. 

The loss of intelligence might have serious security ramifications, particularly for Ukraine as it falters on the battleground. 

For more than a decade, the United States has maintained a secret intelligence collaboration with Ukraine, which is now essential to both nations' efforts to confront Russia, The New York Times reported in February. 

When asked for a response, a Trump campaign representative referred to a statement on TruthSocial claiming the former President "will restore peace and rebuild American strength and deterrence on the world stage."

The officials, along with another US official, reported that the potential limitation of intelligence under a future Trump government was discussed at this week's NATO meeting.

Profound, long-lasting adverse impacts

According to European sources, it is unclear whether the Trump administration intends to resume prior levels of intelligence sharing, which have been in place under Joe Biden, or reduce them further. During Trump's first term, his intelligence agencies shared the usual practices of the US with the country's closest security allies, including those in the Five Eyes Alliance, not going beyond what was necessary or customary. 

Biden, however, has stepped up US intelligence against Russia, giving allies cables, diplomatic contacts around the world, especially in Africa, and briefings for top intelligence chiefs and their counterparts. It has also provided massive intelligence to the Israeli occupation in its war on Gaza.

Read more: US officials frustrated 'Israel' wants US to share more intel: WashPo

John Brennan, former CIA director, stated that such sharing has been "essential" to countering Russia in Ukraine and thwart other Russian activities, adding that any cutoff would have "immediate, profound, and potentially long-lasting adverse impact on Western security interests.”

Over the last three years, US intelligence updated NATO on Russia's operations in Ukraine, including military deployments and tactical advancements, according to a US official, adding that it also shed light on Moscow's alliances with Iran, DPRK, and China.

The US also relies on specific information from European partners, and if Trump withholds intelligence, they will most certainly retaliate, according to a recently retired senior US official.

“There are things our allies know that we don’t that we count on when it comes to certain sources," one US official told Politico.

Another European official cited that “intel sharing is often two-way traffic.”