The United States will regard "any armed attack" on Qatari territory as a threat to Washington and will provide the Gulf Arab state with security guarantees, the White House said on Wednesday, after an Israeli strike on the country last month.

"In light of the continuing threats to the State of Qatar posed by foreign aggression, it is the policy of the United States to guarantee the security and territorial integrity of the State of Qatar against external attack," said an Executive Order signed by U.S. President Donald Trump on Monday and released on Wednesday.

The Russian army's advance in Ukraine slowed again in September, especially in the Donetsk region, according to an AFP analysis of data from the US-based Institute for the Study of War (ISW).

Moscow's forces seized a total of 447 square kilometers (173 square miles) from Ukraine in September, accentuating a slowdown that began in August, the data showed.

France is probing an oil tanker suspected of being part of Russia's clandestine "shadow fleet" for "serious offenses", President Emmanuel Macron said Wednesday -- stopping short of confirming reports of a link to mysterious drone flights in Denmark.

EU chief Ursula von der Leyen Wednesday vowed Russia would not succeed in sowing "division and anxiety" in the bloc, at the start of summit talks in Denmark rattled by a spate of mysterious drone flights.

"It's a pattern, and this pattern is coming from Russia," von der Leyen told reporters as the defence talks kicked off in Copenhagen. "Russia tries to test us, but Russia also tries to sow division and anxiety in our societies. We will not let this happen".

The EU will seek to widen and significantly increase tariffs on foreign steel, the bloc's industry chief Stephane Sejourne told the sector on Wednesday.

Brussels will unveil new measures on Tuesday to protect the steel sector that will replace the current "safeguard clause" expiring next year, Sejourne said during a meeting in Brussels, participants told AFP.

Eurozone inflation rose in September, official data showed Wednesday, buoyed by energy costs in the single-currency area.

Inflation rose to 2.2 percent last month, from two percent in August, the EU's statistics agency said. The figure was in line with predictions by analysts surveyed by Bloomberg.

Israel's defense minister on Wednesday said the military would tighten its encirclement of Gaza City, issuing a final warning for residents there to flee south.

"This is the last opportunity for Gaza residents who wish to do so to move south and leave Hamas operatives isolated in Gaza City," Israel Katz said in a statement shared with Israeli media. "Those who remain... will be considered terrorists and terrorist supporters."

Denmark's support for Ukraine, its lack of anti-drone defenses and this week's EU summit in Copenhagen could all explain the unidentified drone sightings over Danish airspace that have been widely blamed on Russia.

The United States is sending anti-drone defenses to Denmark as it hosts an EU summit this week, Copenhagen's defense ministry said Tuesday, after drones over the Nordic country closed several airports.

Finland, France, Germany, the Netherlands, Norway, Poland and Sweden have also all sent anti-drone technology ahead of the summit to Denmark, which fears Russian surveillance of its military sites.

Iran said Tuesday that 120 nationals being deported from the United States under President Donald Trump's immigration crackdown, will fly home this week.