By Phil Stewart
WASHINGTON (Reuters) - The United States is weighing requests for military assistance from Ukraine, including both lethal and non-lethal support, two U.S. officials said on Thursday, as a prominent U.S. senator urged approval of any arms sought by Kiev.
The U.S. officials, who asked to speak on condition of anonymity because of the sensitivity of the diplomatic discussions, said the United States had already decided to move ahead with some aid, including military food rations.
The U.S. government was still weighing other requests, including for lethal aid, which were made through the U.S. State Department, the officials added, without offering more details.
Earlier on Thursday, the Wall Street Journal reported that Ukraine's interim government asked for arms, ammunition and intelligence support but the United States had decided against further assistance beyond rations because of concerns about stoking tensions with Russia.
Senator John McCain said if the Journal's article were accurate, it would be "deeply disturbing."
"The United States should not be imposing an arms embargo on a victim of aggression," McCain said in a statement.
"Now is the time to show the Ukrainian government and people that the United States stands with them in their hour of greatest need."
Russia launched new military exercises near its border with Ukraine on Thursday, showing no sign of backing down on plans to annex its neighbor's Crimea region despite a stronger-than-expected drive for sanctions from the EU and United States.
U.S. Secretary of State John Kerry said serious steps would be imposed on Monday by the United States and Europe if a referendum on Crimea joining Russia takes place on Sunday as planned.
Still, U.S. officials have emphasized diplomatic and economic tools meant to pressure Moscow, while the Pentagon has moved to reassure NATO allies and partners by gestures including boosting participation in a NATO's Baltic air policing mission.
U.S. Defense Secretary Chuck Hagel, speaking earlier on Thursday before a congressional hearing, also noted Pentagon's decision to suspend military engagements with Russia and boost aviation training with Poland.
"The administration's efforts have been focused on de-escalating the crisis, supporting the new Ukrainian government with economic assistance and reaffirming our commitments to our allies, NATO partners, in Europe," Hagel said.
(Additional reporting by Patricia Zengerle; Editing by Cynthia Osterman)