DAMASCUS, Oct. 31 (Xinhua) -- The U.S.-backed Syrian Democratic Forces (SDF) has temporarily suspended its wide-scale offensive against the Islamic State (IS) in eastern Syria amid Turkish strikes, a war monitor reported Wednesday.

The SDF, which was amassing a large number of forces to have another round of battles against the IS on the eastern bank of Euphrates River, has temporarily halted their offensive after they came under Turkish shelling, according to the Syrian Observatory for Human Rights.

The Britain-based watchdog group said the Turkish side, which has been threatening to launch offensives on the Kurdish-led SDF in the eastern Euphrates, held meetings with Turkish-backed rebels as part of the preparations to launch an offensive on the Kurdish-led groups.

It said the preliminary Turkish shelling Wednesday targeted the SDF positions in the areas of Ayn al-Arab, or Kobane, as well as in the town of Tal Abyad in northern Syria, killing four fighters.

With the shelling, the SDF had to halt the campaign against IS in the group's last pocket in the eastern countryside of Deir al-Zour province in eastern Syria, said the observatory.

The SDF has been on crushing offensive against IS in the eastern Euphrates since Sept. 10, but the terror-designated group succeeded in a counter-offensive recently to recapture all fallen areas from the SDF.

After this setback, the U.S.-backed SDF started amassing forces again for another round of battles to dislodge IS in its last pocket in eastern Syria.

Despite the tension that would grow with the U.S., Turkish President Recep Tayyip Erdogan said Tuesday that his country had finalized plans for a "comprehensive and effective" operation that would target the U.S.-backed Kurdish groups in the east of the Euphrates River.

His remarks came a day after the Turkish forces shelled positions of the Kurdish militia in northern Syria.

The Turkish stance also reflects the desire to defeat the Kurdish militia in the eastern Euphrates after they had already pushed them to retreat from the western side of the river in two cross-border operations in 2016 and 2018.

Throughout the over seven-year-long war in Syria, Turkey has made it clear it won't tolerate a growing Kurdish influence in northern Syria near the Turkish border.

Ankara has already backed Syrian rebels to push the Kurdish forces out of the northern enclave of Afrin earlier this year.