KIEV U.S. Secretary of State John Kerry on Tuesday condemned Russia's "act of aggression" in Ukraine's Crimea region and said Moscow was looking for a pretext to invade more of the country.
Visiting Kiev to show support for Ukraine's new leaders after Russian forces took control of Crimea, Kerry said there was no evidence to support Moscow's version of events - that Russian speakers are in danger in Ukraine.
"The United States reaffirms our commitment to Ukraine's sovereignty and territorial integrity according to international law. We condemn the Russian Federation's act of aggression," Kerry told a news conference in the Ukrainian capital.
"It is clear that Russia has been working hard to create a pretext for being able to invade further," he said. "Russia has talked about Russian-speaking ordinary citizens that are under siege. They are not. And in fact this government has acted remarkably responsibly."
Russian forces have taken over military installations and other buildings in Crimea, a peninsula where Russia's Black Sea Fleet has a base. President Vladimir Putin says he reserves the right to use force as a last resort to protect compatriots.
Washington and its Western allies are exerting pressure on Moscow to pull back its troops or face economic sanctions and diplomatic isolation.
After talks with Acting President Oleksandr Turchinov, Prime Minister Arseny Yatseniuk and Foreign Minister Andriy Deshchytsia, Kerry praised the leaders installed since Moscow-backed Viktor Yanukovich was deposed as president last month.
Criticising the Russian leadership, he said: "It is not appropriate to invade a country and at the end of a barrel of a gun dictate what you are trying to achieve."
He added: "What we are looking for here is a responsible way to meet the needs of the parties ... of Ukraine."
During his visit, Kerry announced an economic package and technical assistance for Ukraine.
A senior U.S. administration official said President Barack Obama's administration would work with Congress to approve $1 billion in loan guarantees to help reduce the impact on Ukrainians of proposed energy subsidy cuts as Kiev seeks international financial assistance to avert bankruptcy.
The United States will also send technical experts to Ukraine to advise its central bank and finance ministry on how to deal with the country's economic challenges and help combat corruption, the official said.
Kerry, who visited Independence Square in downtown Kiev, where protesters for three months demanded the removal of Yanukovich, dismissed suggestions by Putin that Russian speakers were endangered by "lawlessness" in Ukraine.
"Here in the streets today I didn't see anybody who feels threatened except for the potential of an invasion by Russia. I would hope that President Putin ... will step back and listen carefully that we would like to see this de-escalated. We are not looking for some major confrontation," he said.
"We would like to see President Putin address the problems not by deploying forces, not through confrontation but by engaging in the time-honoured tradition of diplomacy, of discussion, of negotiation."
He urged Putin to help "find a path forward which puts everybody on a track that benefits this region a little more effectively".
The United States will train observers for a presidential election on May 25 to bring the electoral process in line with international standards. A team from the Washington-based International Monetary Fund is in Kiev to assess the state of Ukraine's economy.
The United States, the IMF's largest member country, has said it will support an IMF-backed lending program to Ukraine. Part of the IMF's lending conditions are likely to include cuts in energy subsidies that are a drain on government resources.
(Reporting by Lesley Wroughton, Editing by Timothy Heritage and Will Waterman)