Australia has agreed to take charge of searching for a missing Malaysian airliner over a vast section of the Indian Ocean.
Prime Minister Toby Abbott said Australia was boosting surveillance in the area at Malaysia's request.
Meanwhile, Kyrgyzstan said Malaysian Prime Minister Najib Razak had asked President Almazbek Atambaev on March 17 to assist in the search while, for its part, Kazakhstan said it had not detected any "unsanctioned use" of its airspace.
The Kazakh Civil Aviation Committee said that while the jet could hypothetically have reached Kazakh airspace, it would have been detected had it done so.
The Malaysia Airlines plane disappeared on March 8 with 239 people aboard.
Investigators now say evidence points to a deliberate diversion of the plane as the aircraft's key signaling system was intentionally disabled and it flew for as long as seven hours after it disappeared from radar screens.
Investigators also say the last words spoken from the cockpit -- "All right. Good night." -- came after the signaling system was switched off, something experts say the pilots would almost certainly have been made aware of.
Twenty-six countries have been asked to look for the missing plane in two vast areas, to the north from Thailand to Kazakhstan and Turkmenistan, and to the south deep into the Indian Ocean toward Australia.
Based on reporting by AP, Reuters, and RFE/RL's Kyrgyz and Kazakh services