Trump expected to declare victory over Islamic State amid growing opposition

Just hours before US President Donald Trump is expected to tout Washington's successes in Syria during his State of the Union speech, a top United States general warned against the likelihood of an Islamic State resurgence in the war-torn country.

The remarks by General Joseph Votel, head of the US military's Central Command, represent the latest warning by current and former US officials about the risk of an IS resurgence in Syria if Trump’s plan to withdraw more than 2,000 US troops from Syria goes forward.

"We do have to keep pressure on this network.... They have the ability of coming back together if we don't," Votel told a Senate Armed Services Committee hearing on Tuesday.

In his address to the committee, Votel also said he was not consulted ahead of Trump's December announcement on the withdrawal.

In contradiction to Votel and other military and Pentagon officials, a source close to the US president told Reuters that Trump is expected to declare IS all but defeated during his State of the Union address on Tuesday evening.

It is unclear whether Trump's triumphant tone will echo the warnings coming from different parts of his administration, however.

Widespread opposition

The Pentagon's own internal watchdog released a report on Monday saying IS remained active in both Iraq and Syria but was regenerating its functions and capabilities more quickly in the former.

"Absent sustained [counterterrorism] pressure, ISIS could likely resurge in Syria within six to 12 months and regain limited territory," reads the report from the Pentagon's inspector general, using another acronym for IS.

The report, citing information from US Central Command, said IS could portray the US withdrawal from Syria as a "victory" and conduct attacks on American personnel during the pullout process.

Meanwhile, a report by United Nations Secretary General Antonio Guterres warned that IS has transformed into a covert network, including in its strongholds of Syria and Iraq.

The group remains a threat with a centralised leadership, up to $300m at its disposal, and thousands of fighters, according to an 18-page report to the UN Security Council, seen by Reuters on Tuesday.

The report described IS as "by far the most ambitious international terrorist group, and the one most likely to conduct a large-scale, complex attack in the near future".

It also said the group was interested in attacking aviation and using chemical, biological, radiological and nuclear materials, and that up to 18,000 IS militants were in Iraq and Syria, including up to 3,000 foreign fighters.

"Foreign terrorist fighters leaving the conflict zone, or prior returnees becoming active again on release from prison or for other reasons, will increase the threat," the report warned. "Radicalised women and traumatised minors may also pose a serious threat."

Trump's Syria withdrawal has also fuelled rare, vocal opposition from within his own Republican party.

The Republican-led US Senate on Monday backed largely symbolic legislation that openly opposed any abrupt withdrawal of US troops from Syria and Afghanistan.

It warned that "a precipitous withdrawal" could destabilise the region and create a vacuum that could be filled by Iran or Russia.

Last week, US intelligence chiefs also broke with the president, saying IS would continue to pursue attacks from Syria, as well as Iraq, against regional and Western adversaries, including the US.