CEBU, Philippines : The International Monetary Fund (IMF) warned on Tuesday that "tit-for-tat" tariffs could undermine Asia's economic prospects, raise costs and disrupt supply chains even as it expects the region to remain a key engine of growth for the global economy. "The tit-for-tat retaliatory tariffs threaten to disrupt growth prospects across the region, leading to longer and less efficient supply chains," IMF Asia-Pacific Director Krishna Srinivasan said at a forum in Cebu on systemic