U.S. Secretary of Defense James Mattis visited Ukraine on Thursday, and used that opportunity to reaffirm that the United States would continue to support the nation against Russian aggression.

Mattis first attended the Ukranian Independence Day Parade in Kiev, before attending meetings with his Ukrainian counterpart, Defense Minister Stepan Poltorak, as well as President Petro Poroshenko.  After the meetings, Mattis appeared alongside Poltorak for a joint press briefing, in which Mattis accused Russia of failing to honor the Minsk ceasefire agreement that aimed to quell the ongoing conflict in Eastern Ukraine between Russian backed separatists and the local government.

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.”

Mattis went on to declare that the United States would continue to push Moscow to live up to its obligations per the Minsk agreement, which was signed in 2014 but has yet to see Russia fully implement it.

“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.  That Minsk agreement, which was signed by the leaders of Ukraine, Russia, France and Germany, calls for an immediate ceasefire and withdrawal of all heavy weaponry from the region.  It also requires unfettered access for monitors from the Organization for Security and Cooperation in Europe to investigate Ukraine’s Donbas area.

“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.

America’s support for Ukraine has been gaining a higher profile in recent months, as Mattis’ visit marks the second senior official from Trump’s administration to meet with Ukrainian officials in two months.  Secretary of State Rex Tillerson also visited in Kiev in July.

“I’ve been very clear in my discussions with Russian leadership, on more than one occasion, that it is necessary for Russia to take the first steps to de-escalate the situation in the east part [sic] of Ukraine, in particular by respecting the ceasefire,” Tillerson said last month.