"We should be clear about the source of this violence", Tillerson said.
U.S. Secretary of State Rex Tillerson held up the Ukraine crisis Thursday as the sole issue keeping the United States and Russian Federation from forging a closer relationship, arguing that all other disputes are secondary.
Secretary of State Rex Tillerson vowed there will be no easing of sanctions on Russian Federation or warming of relations until Moscow stops supporting separatists in eastern Ukraine and abandons the "apparent annexation" of Crimea in 2014.
"We can have differences in other arenas, in Syria, we can have differences in other areas", he said.
"We will continue to work with Russian Federation to see if we could not agree a peacekeeping force that could enter Ukraine (and) reduce the violence", Tillerson told the news conference.
The OSCE has deployed 600 unarmed monitors in Ukraine to investigate and deter ceasefire violations, but they often come under fire from the warring factions.
Moscow is deeply concerned about the situation with the observance of rights and freedoms throughout the Euro-Atlantic space, the practice of dividing media outlets into "free" and "propaganda" is vicious, Russian Foreign Minister Sergey Lavrov told an OSCE Ministerial Council meeting in Vienna on Thursday.
"Russia is arming, leading, training and fighting alongside anti-government forces". He noted that an American OSCE paramedic working with an observer group was killed in a land mine explosion in April.
Russia's foreign minister called on Organization for Security and Cooperation in Europe (OSCE) countries to strengthen efforts to ensure the safety of the internet on Thursday.
He and Lavrov met on the sidelines of the conference, though both ignored reporters' questions when the meeting began.
The U.S. has decried Moscow's military involvement in eastern Ukraine, where it has backed pro-Russia separatists, and its 2014 annexation of Crimea from Ukraine.