U.S. President Donald Trump directed the U.S. to pause all assistance to Ukraine as he seeks to pressure Ukrainian President Volodymyr Zelenskyy to engage in peace talks with Russia.

The decision appears to halt arms deliveries approved under the Biden administration, but it was not clear whether deliveries of ammunition for weapons systems already in Ukraine would be affected.

Ukraine, which depends heavily on foreign help to hold back the Russian invasion that began on Feb. 24 2022, has feared that aid could be stopped since Trump took office.