MOSCOW -- Russia on Monday condemned the U.S. military's downing of a Syrian warplane, suspending the use of a military hotline that Washington and Moscow have used to avoid collisions in Syrian airspace and threatening to target aircraft flown by the United States and its allies over Syria.
The moves were the most recent example of the intensifying clash of interests between the two powers, which support different sides in the yearslong civil war in Syria.
The Russian military has threatened to halt its use of the hotline in the past -- notably after President Donald Trump ordered the launch of missiles against a Syrian air base in April -- only to continue and even expand its contacts with the U.S. military. It was not clear whether the latest suspension would be lasting.
The move came after an American F/A-18 jet shot down a Syrian government warplane south of Tabqa on Sunday, after the Syrian aircraft dropped bombs near ground forces supported by the United States. It was the first time the U.S. military had downed a Syrian plane since the civil war began in the country in 2011.
The Russian Defense Ministry called U.S. attacks against the Syrian forces "military aggression" and announced that it would suspend cooperation with the United States intended to prevent airborne accidents over Syria.
"All flying objects, including planes and drones of the international coalition, detected west of the Euphrates, will be followed by Russian air defense systems as targets," the Russian Defense Ministry said in a statement.
The United States will continue to conduct air operations over Syria, a spokesman for the U.S.-led coalition that is fighting the Islamic State said Monday.
"We are going to continue to conduct operations throughout Syria, providing air support for coalition and partnered forces on the ground," the spokesman, Col. Ryan Dillon, said in a telephone interview from Baghdad.
Dillon also said the American-led coalition in Syria had repositioned aircraft as a result of Russia's threat to treat its warplanes as targets.
Pentagon officials emphasized that the situation was still unfolding.
"This is a delicate couple of hours," Gen. Joseph Dunford Jr., the chairman of the Joint Chiefs of Staff, said Monday just before speaking at a luncheon at the National Press Club in Washington. He said he had no plans to immediately call his Russian counterpart, Gen. Valery Gerasimov, while the U.S. military was still determining facts on the ground, but that he would talk to him "in time."
During his appearance at the press club, Dunford said the hotline had been used Monday morning and said the United States would work both diplomatically and militarily in the coming hours "to re-establish deconfliction."
Dillon did not provide details on what air operations were underway. After the United States carried out the cruise-missile attack in April at a Syrian airfield that was used to mount a nerve-gas attack, the U.S.-led air war command initially sent armed drones in and around Raqqa instead of piloted aircraft. That was done to guard against the risk of retaliation by Syrian and Russian air defenses.
Weeks after President Vladimir Putin of Russia ordered his country's military forces to Syria in September 2015 to prop up the government of President Bashar Assad, Russia and the United States signed a memorandum on preventing air clashes between the two countries.
Since then, the agreement has been a crucial link that has allowed Moscow and Washington to notify each other about their air operations over Syria, in which Iran, Israel, Russia, Syria, Turkey and the United States with its allies carry out attacks in pursuit of often-competing aims.
But Moscow has tried to use the agreement as leverage each time the situation has threatened to escalate.
The Russians threatened to stop using the hotline after the April cruise-missile strike. But by the next month, the two sides were using it more than ever.
Dillon said the U.S.-led coalition was also prepared to continue using the hotline, which consists of phone calls between the United States' Al Udeid Air Base in Qatar and a Russian base at Latakia, Syria. An unclassified Gmail account is used as a backup.
"The coalition is always available to deconflict with Russia to ensure the safety of our aircrews and operations," Dillon said.
Speaking Monday in Beijing, the Russian foreign minister, Sergey Lavrov, seemed to be unaware of the decision to halt the line communications. He called on the United States and all other countries involved in the Syria conflict to "coordinate their actions."
"We urge everyone to avoid acting unilaterally, to respect the sovereignty of Syria," he said.
In Moscow, Frants Klintsevich, the deputy chairman of the Russian Senate's defense committee, called the downing of the Syrian warplane a "blunt act of aggression and provocation."
"It is Russia that is being provoked most of all," Klintsevich wrote in a Facebook post. "It seems that the United States under Donald Trump is the source of danger for the Middle East and the whole world on a qualitatively new level."
In Washington, White House spokesman Sean Spicer told reporters that "we're going to continue to keep an open line of communications with the Russians" and the "escalation of hostilities among the many factions that are operating in this region doesn't help anybody."
Spicer added that "we will retain the right of self-defense of coalition forces aligned against" the Islamic State.
The mulitfaceted escalation Spicer described was underscored Sunday when Iran -- which, like Russia, backs Assad -- fired missiles at Islamic State targets in Syria in retaliation for deadly attacks by the jihadis in Tehran on June 7.
Iran, for its part, said its strike targeting the Islamic State in Syria was not only a response to deadly attacks in Tehran, but a powerful message to archrival Saudi Arabia and the United States.
"The Saudis and Americans are especially receivers of this message," Gen. Ramazan Sharif of the Revolutionary Guard told state television in a telephone interview. "Obviously and clearly, some reactionary countries of the region, especially Saudi Arabia, had announced that they are trying to bring insecurity into Iran."
The launch, which hit Syria's eastern city of Deir el-Zour, appeared to be Iran's first missile attack abroad in over 15 years and its first in the Syrian conflict, in which it has provided crucial support to Assad.
Information for this article was contributed by Ivan Nechepurenko, Michael R. Gordon and Elisabeth Bumiller of The New York Times; by Dana Khraiche, Ilya Arkhipov and Jennifer Epstein of Bloomberg News; and by Nasser Karimi and Jon Gambrell of The Associated Press.
A Section on 06/20/2017
