The presidents of Uzbekistan and Kazakhstan called for the United Nations to review the potential impact of two disputed hydroelectric dams proposed by their regional rivals Tajikistan and Kyrgyzstan.
Iran's defiant expansion of its nuclear programme and 10 failed meetings with the IAEA will dominate a gathering of the UN body's board starting Monday.
Failure to agree on who will take part in an international conference on the Syria could thwart hopes that the make-or-break meeting will be held in June.
North Korea fired another short-range missile into the Sea of Japan on Monday, the latest in a series of missile drills that have been condemned by South Korea and UN chief Ban Ki-moon.
South Korea on Monday predicted further missile tests by North Korea which fired four short-range missiles into the Sea of Japan at the weekend, drawing criticism from Seoul and UN chief Ban Ki-moon.
The UN General Assembly condemned President Bashar al-Assad's "escalation" of the Syrian war on Wednesday as rebels battled to free inmates from a prison in the key city of Aleppo.
Nuclear talks between Iran and the UN atomic agency failed yet again Wednesday, as the top US diplomat in separate six-party negotiations warned Washington's patience was wearing thin.
Former head of Kazakhstan private airline East Wing Aleksandr Zykov suspected by UN expert of implication in deals in weapons for North Korea pleads not guilty.
Two sets of talks on Wednesday aimed at easing tensions over Iran's nuclear programme are not expected to produce any major breakthrough ahead of next month's elections in the Islamic republic.
Israeli raids early Sunday hit three military sites outside Damascus, the second such reported attack in 48 hours, prompting Syria's government to warn that the regional situation was now "more dangerous."
UN Secretary-General Ban Ki-moon appealed Sunday for restraint to avoid an escalation in Syria's civil war, expressing "grave concern" over Israeli air raids.