(Adds quotes from lawmakers, background, details on IMF)
By Patricia Zengerle
WASHINGTON, March 27 (Reuters) - The U.S. Senate and House of Representatives easily passed bills on Thursday to provide aid to Ukraine, back a $1 billion loan guarantee for the Kiev government and impose sanctions on Russians and Ukrainians over Russia's annexation of Crimea.
The Senate passed its legislation by voice vote and the House voted for its legislation by 399-19, two days after Senate Democrats ended a weeks-long standoff by agreeing to remove from the legislation reforms to the International Monetary Fund urged by the White House but opposed by many Republicans.
Lawmakers said they wanted to send a unified message to Russian President Vladimir Putin - and the rest of the world - as Ukraine and neighboring states worry about more aggression from Russia.
"I believe we are in a dangerous moment in history with global consequences and the world is watching," Robert Menendez, chairman of the Senate Foreign Relations Committee, told a news conference shortly after the Senate vote.
President Barack Obama has been in Europe this week urging U.S. allies to stand together to counterbalance Moscow.
The Senate and House will have to agree on how to handle differences between the two pieces of legislation before a final bill can be sent to Obama, who is expected to sign it into law.
Menendez, a New Jersey Democrat, said congressional leaders had reached an agreement under which the House will vote on the Senate bill and it would get to Obama by the end of the week.
In addition to the loan guarantee, the Senate bill provides $150 million in aid to Ukraine and neighboring countries, and formalizes sanctions on Russians and Ukrainians who the United States deems responsible for corruption, human rights abuses or undermining stability in Ukraine.
Obama announced sanctions against Russian President Vladimir Putin's inner circle last week, but congressional approval makes them mandatory. The Senate bill also would impose sanctions on a broader category of individuals than Obama's order.
Lawmakers said they considered the bill only a first step. They said Congress should consider more legislation in the weeks ahead to impose more sanctions to punish Moscow, provide military aid for Ukraine and boost U.S. energy exports to lessen Europe's reliance on Russian natural gas.
Senator Bob Corker of Tennessee, the top Republican on the Senate Foreign Relations panel, said that over time, once Ukraine is stabilized, there will be an effort to provide "some type" of U.S. military assistance for Kiev.
Separately, the United States said on Thursday it had imposed a ban on issuing licenses for military items to Russia in response to Russia's annexation of Crimea.
Some Democrats in Congress said they were pleased a Ukraine bill had finally passed but still wanted approval of the IMF reforms.
The White House has been trying for years to win Congress' approval for a shift of $63 billion from an IMF crisis fund to its general accounts, making good on a commitment from 2010.
The Obama administration had said the approval was especially important because of the vital role the international lender would be playing in the Ukraine crisis. But many Republicans, uncomfortable about potential costs to U.S. taxpayers and a possible reduction in U.S. influence at the IMF, insisted the two things were unrelated.
Supporters of the reform deny there would be any cost to taxpayers and say failure to approve the change, rather than approval, could put U.S. influence at risk.
The IMF announced an agreement on Thursday for a $27 billion bailout for Ukraine to help the heavily indebted ex-Soviet republic stabilize its economy after three months of protests that resulted in the ouster of its pro-Moscow president, prompting Russia to annex Crimea.
"This agreement highlights the important role the IMF can play in preventing economic catastrophe," said Maryland Representative Steny Hoyer, the No. 2 Democrat in the House, urging lawmakers to reconsider the IMF reforms.
(Additional reporting by Richard Cowan, editing by Cynthia Osterman)