U.S. Assistant Secretary of the Treasury for Terrorist Financing Daniel Glaser reportedly warned during a short visit to Beirut from attempts to involve Lebanese banks in money laundering operations to finance terrorism.

According to al-Akhbar newspaper published on Wednesday, Glaser, who met with Central Bank Governor Riad Salameh and a delegation from the Lebanese Association of Banks, said that funds to the Islamic State of Iraq and the Levant (ISIL) from some Gulf countries could pass through Lebanon, Iraq and Turkey.

A brain-damaged 74-year-old man who killed a police officer was executed on Tuesday in Missouri after his final Supreme Court appeal was rejected, prison authorities said.

Cecil Clayton was pronounced dead by lethal injection at 9:21 pm (0221 GMT), said Mike O'Connell, spokesman for the Missouri prison service.

The White House this week was sent a letter that tested positive for cyanide, U.S. media reported Tuesday, in yet another piece of bad news for the Secret Service.

"On Monday 3/16/15, an envelope was received at the White House Mail Screening Facility. Initial Biological testing was negative; however, on 03/17/15, the chemical testing returned a presumptive positive for cyanide," Secret Service spokesman Brian Leary said in a statement on CNN. "The sample was transported to another facility to confirm the results."

Syria's military shot down a U.S. drone over the coastal province of Latakia, a stronghold of President Bashar Assad, state media said on Tuesday.

The U.S. military confirmed that it had lost communication with an unarmed Predator drone over northwest Syria on Tuesday and was looking into the claims it was brought down.

The director of the U.S. Secret Service faced a grilling Tuesday from U.S. lawmakers upset by its failure to rein in embarrassing security lapses, and by his acknowledgement that agents use alcohol to reduce stress.

Joseph Clancy, the tarnished protection agency's new boss, was in the hot seat over an incident early this month in which two senior agents drove into White House barricades after a night of boozing but were not detained or given breathalyzer tests.

Hizbullah and Iran are no longer enrolled on a U.S. list of terror threats, according to an annual report by the U.S. National Intelligence that was delivered to the Senate.

Hizbullah and Tehran, which comprise along with Syria and other organizations the “axis of resistance” that oppose Israel and Western policies in the Middle East, have exerted efforts to combat the Islamic State group in Iraq and Syria.

Turkish Prime Minister Ahmet Davutoglu on Tuesday rubbished suggestions that talks should be held with President Bashar Assad, saying negotiating with the Syrian leader was no different to shaking hands with Nazi tyrant Adolf Hitler.

U.S. Secretary of State John Kerry said in a weekend interview that Washington would have to talk with Assad eventually if peace was to be forged, in comments that drew a strong rebuke from Ankara which said there was nothing to negotiate with Assad.

South Korea's government accused North Korea Tuesday of carrying out cyber-attacks last December on its nuclear power plant operator, describing them as a  provocation which threatened people's lives and safety.

"It's a clear provocation against our security," the unification ministry said after investigators concluded that the North was behind the attacks.

The U.S. hunkered down Tuesday with Iran for crunch talks while warning that key disagreements remain ahead of a March 31 deadline to agree the outlines of a major nuclear deal.

"There is no way around it, we still have a ways to go," a senior U.S. official involved in the talks in the Swiss lakeside city of Lausanne said Tuesday.

U.S. forces played a "substantial" role in a botched anti-terrorism raid in the Philippines that left 44 local police commandos dead, according to a Senate report released Tuesday.

The raid, known locally as Oplan Exodus, has plunged President Benigno Aquino's administration into crisis and jeopardised efforts to end a decades-long Muslim separatist insurgency.