As fighting intensifies in Ukraine, the Unites States Secretary of State, John Kerry, is expected to arrive in the country to hold talks with President Petro Poroshenkom, and his Prime Minister, Arseniy Yatseniuk.
A superior source said that Kerry would offer U.S. support for efforts by Ukraine to negotiate a new ceasefire.
The issue of weapon deliveries to Ukraine and other U.S. assistance is expected to be one of the main items on the agenda.
Kerry also intends to provide an additional $16.4 billion in humanitarian aid to help civilians in eastern Ukraine, U.S. officials said.
Earlier, Ashton Carter, the White House’s choice for Defence Secretary, said that he was “inclined” to start supplying arms.
The U.S. has so far only provided “non-lethal” assistance to Ukraine.
Meanwhile, NATO is set to unveil what the bloc’s chief says are “the biggest reinforcement” of its “collective defense since the end of the cold war”.
However, Russia denies accusations by Ukraine and the west that it is arming the rebels in Eastern Ukraine and sending its regular troops across the border.