Former US President Donald Trump’s special envoy for Ukraine, Keith Kellogg, said the United States should reconsider its current collective defense system and did not rule out leaving NATO to create a new military bloc.

Speaking on Fox News, he expressed the view that the alliance in its current form does not meet security challenges and requires major changes. In his assessment, an alternative could be the creation of a new defense structure that would include a number of countries, such as European states, as well as Japan, Australia, and possibly Ukraine.

Kellogg also noted that NATO rules allow a member state to leave the alliance with a one-year notice.

Earlier, Donald Trump questioned NATO’s ability to effectively support the United States, criticizing the alliance for what he described as poor treatment and insufficient effectiveness in responding to global threats, including in the context of the operation against Iran.