UN chief: IS on defensive in conflict areas but is adapting

U.N. Secretary-General Antonio Guterres says the Islamic State extremist group is on the defensive in Afghanistan, Iraq, Libya and Syria but is partially adapting to the pressure by moving to covert communications and recruitment and expanding its areas of attack.

The U.N. chief says in a report to the Security Council circulated Monday that the threat of attacks on airports and aircraft "remains high" and IS continues to encourage its supporters outside conflict areas to perpetrate attacks.

Guterres says the militant group's financial condition continues to deteriorate, forcing it to operate on a "crisis" budget. He says IS recruitment is down and its fighters are increasingly leaving the battlefield.

But he says the extremist group's revenue streams remain the same — income from oil and gas, extortion and "taxation."