In his trip to Ukraine to attend its independence day parade on Friday, Trump adviser John Bolton gave a news conference in Kiev and talked about supporting Ukraine and sanctioning Russia.
Bolton said: “US sanctions against Russia to remain in place until there is change in Russia's behavior.”
He added that he sees progress in Ukrain’s efforts to join NATO but that the country “still has more to do before it can join NATO.”
“Ukraine government should consider inviting US companies to explore gas in Ukraine,” he said.
Ukraine marked 27 years of independence Friday with its biggest ever military parade in central Kiev, as war continues against Russian-backed separatists in the country's east.
Around 4,500 servicemen, including dozens of representatives of foreign allies such as the United States and Great Britain, saluted Ukrainian President Petro Poroshenko during the demonstration.
Poroshenko used the occasion to argue for the vital role Ukraine plays in defending the borders of Europe.
Without the territorial integrity of Ukraine, “all borders in Central and Eastern Europe will be uncertain” he said.
“Russia’s war against Ukraine is part of the Kremlin’s plan to ruin the EU and NATO,” the president added.
“I want to stress that Europe needs us, because the EU would be an incomplete project without us.”
Some 250 pieces of military hardware including multiple-launch rocket systems were shown to thousands of spectators, many of them waving Ukrainian blue and yellow flags.
As part of the military show, in which last year just 70 pieces of hardware were displayed, army helicopters and jets flew over Kiev’s main street.