What does Ukraine pledge to do in the summit?

As leaders from nearly 50 countries meet in Washington for a major summit on Nuclear Security, (9) Ukraine has pledged to eliminate stockpile of highly enriched uranium by 2012. Ukraine will also convert several nuclear research facilities to use low enriched uranium. The summit, the biggest international meeting hosted by the US since 1945, has been called by President Obama. Our diplomatic correspondent Jonathan Marcus reports from Washington. The timing may have been choreographed for the decision by the Ukraine authorities is just the sort of news President Barack Obama wants to hear. (10) This summit is all about securing stocks of fissile material, highly enriched uranium and plutonium that could potentially be used by terrorists to build a nuclear bomb. US officials said that Ukraine has sufficient highly enriched uranium for several nuclear weapons. This will be removed with some help from the United States. This is a precedent Obama would like other countries to follow and just to underscore the gravity of the potential threat. John Briton, a senior US counter-terrorism official, has warned that al-Qaeda has been seeking material for a nuclear bomb for over 15 years and that interest remains strong.