US Vice President Joe Biden will announce a package of technical assistance focused on energy and economic aid distribution during a two-day visit to Ukraine that began on Monday, a senior administration official said.
Biden is the highest ranking US official to visit the country since the crisis with Russia erupted months ago.
His trip is largely symbolic but during talks with Ukrainian leaders on Tuesday he will announce US assistance, primarily of technical know-how to boost energy efficiency as well as production in Ukrainian natural gas fields and extraction of "unconventional" gas resources, a senior administration official told reporters traveling on board the vice president's plane.
A US team was also in Ukraine to help deal with the issue of securing gas flows from EU countries such as Slovakia and Hungary in the event that Russia cuts off Ukraine's supply, the official said.
Kiev gets about half of its gas from Moscow and a large proportion of Europe's gas is pumped from Russia via Ukraine. The United States is pushing Ukraine and the European Union to diversify their energy supplies and become less reliant on Russia.
Biden arrived in Kiev as an agreement reached last week to avert wider conflict in Ukraine began to falter.
Pro-Moscow separatist gunmen have maintained their grip on seized government buildings across swathes of eastern Ukraine as Washington threatens to impose new economic sanctions on Moscow, which it says it will hold responsible.
"(Biden) wanted to come to Kiev to send a very clear message of the United States' support for Ukraine's democracy, unity, sovereignty and territorial integrity," the official said. "He will call for urgent implementation of the agreement reached in Geneva last week while also making clear ... that there will be mounting costs for Russia if they choose a destabilizing rather than constructive course in the days ahead."
The economic portion of Biden's package will involve US teams helping Ukraine ensure international aid was allocated effectively in all parts of the country, the official said.
Biden will also discuss a recent US tranche of security aid, excluding weaponry, for Ukrainian forces such as blankets and helmets and options for following up on that.
"He'll have the opportunity to speak with the government about what more is needed and what more we could provide in the period ahead," the official said.
Biden is scheduled to meet with Ukraine's acting president, Oleksander Turchinov, and Prime Minister Arseny Yatseniuk on Tuesday. He will also see members of Ukraine's parliament and representatives from non-governmental organizations.
(Editing by Susan Fenton)