A primary goal of the United States "is to restore Ukraine's territorial integrity and sovereignty", he said.
The State Department announced on July 7 that Tillerson would be accompanied to Kyiv by Kurt Volker, a former USA ambassador to North Atlantic Treaty Organisation whom Trump's top diplomat has appointed as a special envoy to negotiate over the fate of war-racked Ukraine.
Kiev and its European allies have been alarmed by Mr Trump's determination to improve relations with the Kremlin, despite its role in Ukraine and alleged meddling in last year's USA presidential election campaign.
In surprisingly blunt language just two days after presidents Donald Trump and Vladimir Putin met in Germany, Tillerson said Russian Federation should use its influence with separatists in Ukraine's east to fully restore an oft-violated truce, end harassment and attacks on worldwide monitors and pull back heavy weaponry to lines agreed upon under a two-year-old accord known as the Minsk Agreement. The President of Ukraine Petro Poroshenko and U.S. Secretary of state Rex Tillerson hold talks in Kiev. According to a senior state Department official, Tillerson during the visit will present to the Ukrainian President his view of the conflict in Eastern Ukraine.
When pressed on the question, Mr. Tillerson used language he had used Friday night, as the meeting in Hamburg broke up, calling the election hacks the "first topic for discussion".
Tillerson told reporters Sunday that the U.S.is going to have a dialogue on how to gain such assurances from their Russian counterparts, adding "the important thing is how do we assure that this doesn't happen again".
Mr. Tillerson suggested that the two leaders would never reach a common understanding of what happened previous year.
"Ukraine's come a long way, you know we want to acknowledge that, and we still have more to do".
"The election interference really shows how complicated the use of these types of tools are becoming".
The US imposed sanctions against Russian Federation, with the latest expansion in late June, after Russia's reunification with Crimea following a 2014 referendum. Prior to that, he worked at the National Security Council and on European affairs at the State Department. The United States is deeply inside Russian computer networks - for surveillance, and if need be to conduct offensive action - and the same is true about Russian penetration of American networks.