The United States and Ukraine signed a deal Monday to remove the former Soviet country's stockpile of weapons-grade uranium by early next year.
Secretary of State Hillary Rodham Clinton and Ukrainian Foreign Minister Kostyantyn Gryshchenko represented their nations in signing the agreement to remove the stockpile, which could provide enough material to build several nuclear weapons.
The deal was announced last year at an international nuclear security conference hosted by President Barack Obama but was not formalized until Monday.
Clinton and Gryshchenko had hoped to sign the deal in July, but it was delayed amid Ukrainian reservations, according to U.S. officials. Among other reasons, Ukraine wanted assurances that the United States would complete a $25 million nuclear research facility called for under the deal.
The research facility will be able to produce 50 different types of medical isotopes, using only low-enriched uranium and Clinton said the U.S. was fully committed to meeting the timelines for constructing the facility so it would be up and running by 2014.
The Ukrainian government also wanted to ensure that the uranium deal was properly approved under government regulations. The government may be particularly sensitive, because former Prime Minister Yulia Tymoshenko was arrested and charged with not obtaining proper approval when signing a natural gas import contract with Russia in 2009.
Clinton praised Ukraine for making the "bold commitment" to world security.
"This deal is a win-win for both countries and both peoples," she said. "It provides tangible benefits for the people of Ukraine and it makes the world safer for all people."
The agreement calls for Ukraine to remove all of its bomb-grade uranium to Russia by April 2012. The material would be blended down and made useless for bombmaking. Late last year, the United States helped Ukraine make the first shipment of 110 pounds.
Clinton also took the opportunity to gently chide the Ukrainians for recent backsliding on democratic principles, saying that the 20th anniversary of Ukraine's independence in 2011 is an opportunity to reflect on U.S.-Ukrainian relations. She noted that it isn't easy to build a democracy from the collapse of a Soviet republic, but said the U.S. wanted to see improvements.
"We are very committed to democratic progress continuing in Ukraine and therefore it is vital that the government avoid any actions that could undermine democracy or the rule of law or political participation," she said. She did not elaborate but her comment was a clear reference to the case of Tymoshenko.
The United States has criticized the arrest as politically motivated and said it raises questions about Ukraine's commitment to the rule of law.