Donald Trump has demanded that allies send warships to help reopen the Strait of Hormuz, putting Europe on another collision course with the US.
The US president was expecting firm military commitments from European leaders within days, Der Spiegel reported on Thursday.
In an apparent reference to his demand, Mr Trump posted on Truth Social that Nato members would not act “unless they have pressure placed upon them”.
A Nato spokesman added that the US expected “concrete commitments and action to ensure freedom of navigation in the strait”.
Mark Rutte, Nato’s secretary-general, met Mr Trump in Washington on Wednesday. They reportedly discussed the plans, which were then passed on to European leaders, who were warned that mere political support would no longer suffice.
Iran’s deputy foreign minister said on Thursday that the strait was “open” despite traffic having remained at a virtual standstill since the temporary ceasefire was agreed.
Tehran indicated that it would start charging fees for ships transiting the vital waterway, in a move that has been met with criticism in Europe.