US President Donald Trump is ready to provide security guarantees for Ukraine, but not within NATO, Politico reports.

This information was reported by three sources: a European diplomat, a British official, and a person briefed on the phone conversation between Trump and European and Ukrainian leaders on Wednesday.

According to these sources, the US was willing to play some sort of role in providing Ukraine with the means to deter future Russian aggression if a ceasefire is reached. The person briefed on the call said, however, that Trump said he would only make such a commitment if the effort is not part of NATO.

Also, Trump did not specify what he meant by “security guarantees,” and only discussed the broader concept, the person briefed on the call said.

Trump recognizes that an American security guarantee must be part of a final settlement and sees the US as playing a role in that, the British official said.

Whatever the security guarantees may be, Trump has made clear that the US will not continue to provide weapons or troops directly to Ukraine, though he will sell weapons to Europe to be used by Kyiv. 

It also is likely to be limited—and is sure to disappoint Ukraine’s backers who want more robust assurances from the US to deter Russia from invading Ukraine again once the fighting is over, Politico added.