Jan 10 (Reuters) - U.S. President George W. Bush will unveil on Wednesday his new plan for Iraq that includes a 21,500 increase in U.S. troops and and reconstruction efforts aimed at halting sectarian violence. Following are the details of the plan as described by senior administration officials. TROOP INCREASE * Bush plans to send 17,500 troops to Baghdad and 4,000 to the volatile Anbar province. * The increases will take place in waves, with the first combat brigade, around 3,500 to 4,000 troops, to arrive in Baghdad on Jan. 15 and the second one on Feb. 15. After that additional brigades will be added every 30 days to reach a total of five in Baghdad. * Two Marine regiments will comprise the 4,000 troops to be added in Anbar. COSTS * When Bush unveils his annual budget on Feb. 5, he will ask Congress for $6.8 billion to cover the new proposals. * Of that, $5.6 billion would pay for the troop boost, with $1.2 billion for rebuilding and jobs programs. * The $6.8 billion will be added to a broader war-spending package for fiscal year 2007 whose price-tag was already expected to hit $100 billion. The current fiscal year is on track to become the costliest yet for the Iraq war. IRAQI CONTRIBUTIONS * The Iraqi government will send three brigades to Baghdad. The first is to arrive on Feb. 1 followed by two more on Feb. 15. * The Iraqis have agreed to spend $10 billion on reconstruction. * The Iraqi command would be multisectarian with one overall commander and two deputies. Another Iraqi commander in each of Baghdad's nine districts would operate out of police stations and be in charge of patrols, checkpoints and door-to-door operations. REGIONAL DIPLOMACY * Bush will call on Iran and Syria to play a constructive role in Iraq but he will not offer new diplomatic initiatives with either country. * U.S. Secretary of State Condoleezza Rice leaves on Friday for a trip to the Middle East where she will seek the help of Arab countries to help stabilize Iraq. * Iraqi Prime Minister Nuri al-Maliki is likely to call for a regional conference in Baghdad that will include Iran and Syria as well as other neighbors.