WASHINGTON, May 27 (Xinhua) -- U.S. Vice President Joe Biden on Wednesday called on Ukraine to implement laws to fight corruption and push forward political reforms amid the current crisis.

"Ukraine needs to use all the tools at its disposal to limit the ability of the oligarchs to abuse their market position or exert pressure on government officials," Biden said in a speech at the Brookings Institution, a Washington-based think tank.

He said Kiev needs to keep working toward constitutionally forming decentralization to ensure the local government is representative and accountable.

"So long as Ukraine leaders keep faith with the project of reform, the United States will continue to stand with them," the Vice President added.

Biden noted that the U.S. has provided with Kiev over 470 million U.S. dollars in economic assistance since the start of the Ukraine crisis more than a year ago, adding that the aid includes nearly 200 million dollars to the armed forces, national guard and border services.

The U.S. and its European partners have imposed several rounds of sanctions against Russia over Moscow's annexation of Crimea and alleged support of separatists in eastern Ukraine. More than 6,000 people have been killed in the fighting that broke out in eastern Ukraine in April last year.

Critics are calling on the U.S. to provide lethal aid to Kiev to fight against Russian-backed rebels. The Obama administration has refused to do so for fears that it may result in greater bloodshed in an escalated conflict.

On Wednesday, Biden said whether the U.S. should provide additional defensive lethal weapons to Ukraine is a debate "worth having."

"But let's not lose sight of the fact that Ukraine also needs basic military equipment and training, which we are also providing on the ground," Biden added.