has demanded the Islamic State group immediately release two hostages. Images of the hostages appear in a new video from the militant group. The video also showed an English-speaking militant holding a knife. He identified the two hostages as Kenji Goto and Haruna Yakawa. The militant criticized Japan for, what he called, its "foolish" support for Western military efforts against the Islamic State. He threatened to execute them if Japan does not pay the group $200 million.Japanese forces are not part of the United States-led coalition against the Islamic State. Coalition forces have carried out more than 1,700 airstrikes against Islamic State targets since August.Last Saturday, Mr. Abe promised to give $200 million in non-military aid to countries fighting the militant group.The International Monetary Fund has cut its estimate for international economic growth in 2015. The IMF now says it expects the world's economy to grow 3.5 percent this year. That compares with an estimate of 3.8 percent, which was made last October.The IMF's chief economist, Olivier Blanchard, said he expects the world's economy to grow somewhat faster this year than it did in 2014. Oil prices and changes in monetary exchange rates were two areas the group described in its latest report.Mr. Blanchard said the drop in oil prices will help support world economic growth. But he notes that the price reduction will not help everyone.China has reported its slowest economic growth in 24 years. The government said the Chinese economy grew by only 7.4 percent in 2014, a little less than the predicted growth rate of 7.5 percent.Observers say the growth rate is not as bad as it could have been. They noted that China faced a number of problems last year. The number of bad loans rose, credit collapsed and land values fell.The World Bank says world markets could be affected if the Chinese economic slowdown continues. They said the slower growth rate might limit the influence of increasing economic activity in the U.S. and British labor markets.In the United States, President Barack Obama is preparing for his State of the Union speech to Congress Tuesday night. Mr. Obama will call for raising taxes on profits individuals make from selling investments such as stocks, bonds and property. The president wants to use the money collected to help reduce taxes for middle class Americans and for proposals such as free community college classes. The Republican Party now holds a majority of seats in both the U.S. Senate and the House of Representatives. Republican lawmakers have already rejected many of Mr. Obama's proposals.