US President Joe Biden has ruled out sending F-16 fighter jets to Ukraine, despite renewed calls from Ukrainian officials for air support.
Asked by a reporter on Monday if the US would be providing the planes, Mr Biden replied simply "no".
His comment comes a day after Germany's leader also ruled out sending fighter jets.
Ukraine has said it needs the jets to take control of its airspace in its ongoing war with Russia.
F-16 Fighting Falcons are widely considered one of the world's most reliable fighter jets and are used by other countries, such as Belgium and Pakistan.
They would be a significant upgrade on the Soviet-era fighting jets Ukraine is currently using, which were made before the country declared independence from the USSR more than 30 years ago.
However, Mr Biden has repeatedly rebuffed Ukraine's pleas for the jets, instead focussing on providing military support in other areas.
The US announced last week that it would supply Kyiv with 31 Abrams tanks, with the UK and Germany also pledging similar support.
Ukraine's Deputy Foreign Minister, Andrii Melnyk, welcomed that announcement but asked allies for the creation of a "fighter jet coalition" that would also provide Ukraine with Eurofighters, Tornados, French Rafales and Swedish Gripen jets.
In an interview on Sunday, Germany's Chancellor said that it "seemed frivolous" to discuss sending other military aid to Ukraine when they had just committed to sending the Leopard 2s.
Olaf Scholz also reiterated to the German newspaper Tagesspiegel that the Nato military alliance was not at war with Russia and that it would "not allow such an escalation".
Moscow has accused Nato of being an aggressor by proxy and members of the alliance, including the US and Germany, have been reluctant to send military aid that could see the conflict escalate.
The French President, Emmanuel Macron, on Monday echoed this sentiment - saying that while "nothing is excluded" when it comes to providing support to Ukraine, it must neither further inflame the situation nor limit France's ability to defend itself.
Other EU countries, including the Netherlands, have not yet given a definitive response on whether they will send fighter jets.
However, Poland has indicated that it would be prepared to supply fighter jets in co-ordination with Nato.
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