MANILA, Philippines (AP) -- Philippine President Rodrigo Duterte has asked Congress to extend martial law in the southern third of the country until the end of the year because the rebellion there will not be completely quelled by July 22, the end of his 60-day martial law proclamation, his spokesman said Tuesday.
Duterte declared martial law on May 23 following a bloody siege of the southern city of Marawi by Islamic State group-aligned militants, the most serious security crisis he has faced since assuming power in June last year.
In a letter to the Senate and the House of Representatives read by his spokesman Ernesto Abella, Duterte said that after consulting security officials, he has concluded that the rebellion in the south will not be quelled completely by July 22.
He asked Congress to extend martial law until Dec. 31.
Under the constitution, in case of invasion or rebellion, when public safety requires it, the president can declare martial law for no more than 60 days. He can ask Congress to extend such a proclamation to a period of time to be determined by the lawmakers.
More than 550 people, including 413 militants, have been killed in nearly two months of fighting in Marawi, a bastion of Islamic faith in the south.
U.S. Ambassador Sung Y. Kim said the United States will be sending two surveillance aircraft to help Philippine forces battling the militants in Marawi. The two Cessna 208 aircraft fitted with intelligence, surveillance and reconnaissance equipment "will be turned over to the Philippines in a couple of weeks," he told ABS-CBN News Channel.
"We're deeply concerned about the security situation in Marawi," Kim said. The U.S. has been providing munition, intelligence and surveillance equipment and special operations troops to advise the Philippine military in the south. It will also assist in rebuilding Marawi, he added.
Duterte met with lawmakers late Monday. He called for a special session of Congress, which is on break, on Saturday to tackle the proposed extension of martial law.
Congress opens its new regular session on July 24, when Duterte delivers his State of the Nation address.
Opposition lawmakers said they will oppose the extension and question its basis.
"It is totally not justified" and "just a whimsical misuse of power," said Sen. Antonio Trillanes IV, adding that the military says the number of militants was down to 60.
"I have already forewarned the public of Duterte's authoritarian tendencies and this is further proof of it," he added.
Rep. Tom Villarin of the left-wing political party Akbayan said it was "a whimsical proposal that has no substantive grounds other than the president's wishes."