US Defense Secretary James Mattis vowed continued US support for Ukraine in the face of Russian "aggression" as he met with the country's leaders in Kiev on Thursday.
Mattis attended a Ukranian Independence Day parade in the capital before sitting down with his Ukrainian counterpart, Defense Minister Stepan Poltorak, and President Petro Poroshenko.
Speaking alongside Poroshenko at a news conference, Mattis said he intended to strengthen the US relationship with Ukraine in the face of Russia's annexation of Crimea in 2014 and the ongoing conflict with pro-Russian separatists in eastern Ukraine.
"Have no doubt, the United States stands with Ukraine. We support you in the face of threats to sovereignty and territorial integrity, to international law, and to the international order writ large," he said.
"We do not, and we will not, accept Russia's seizure of Crimea and despite Russia's denials, we know they are seeking to redraw international borders by force, undermining the sovereign and free nations of Europe."
US Defense Secretary James Mattis (left) and Ukrainian President Petro Poroshenko meet in Kiev, Ukraine, on Thursday.
Mattis said the United States would continue to pressure Moscow to live up to its commitments under the 2014 Minsk
agreement, saying Russia had "put its reputation on the line" when it signed up to the deal, never fully implemented.
"The US will continue to press Russia to honor its Minsk commitments and our sanctions will remain in place until Moscow reverses the actions that triggered them," he said.
The Minsk agreement calls for an immediate ceasefire, withdrawal of all heavy weapons and unfettered access to monitors from the Organization for Security and Cooperation in Europe to Ukraine's Donbas area, which takes in the Luhansk and Donetsk regions. It was negotiated by the leaders of the so-called Normandy Four -- Ukraine, Russia, France and Germany.
"We in the United States understand the strategic challenges associated with Russian aggression -- alongside our allies, we remain committed to upholding the widely accepted international norms that have increased global stability for decades," Mattis added.
Mattis said he would go back to Washington with a clearer idea of the needs of Ukrainian soldiers on the front line.
A key issue is whether the United States should provide Ukraine with defensive armaments, such as anti-tank missiles, in addition to non-lethal military equipment.
The United States has approved the provision of nearly $750 million-worth of military equipment in recent years, Mattis said.