The US-mediated talks are the latest chapter in the so far unsuccessful diplomatic effort to halt the war in Ukraine.

U.S., Russian and Ukrainian negotiators are back around a table for a second round of technical talks, but in Kyiv, Russian bombs bring suffering and skepticism.

Fiber optic drones and other tethered Unmanned Aircraft Systems are providing major advantages to military forces and posing new threats.

By Gram Slattery and Humeyra Pamuk WASHINGTON, Jan 30 (Reuters) - U.S. and European officials are growing increasingly worried as hundreds of millions of dollars in U.S. energy assistance previously pledged for Ukraine remain unreleased,