The United States will increase the tempo of operations in support of ground forces in Iraq and Syria as they prepare to tackle the Islamic State’s twin capital cities, according to the new commander of the U.S. military operations against the militant group.

Lt. Gen. Stephen J. Townsend, who takes command on Sunday of U.S. and allied operations against the Islamic State, said U.S.-backed forces in Iraq and Syria were preparing to move on the Iraqi city of Mosul and the Syrian city of Raqqa for what he said would be the conclusive urban battles.

Speaking in a phone interview, Townsend said that “our job is to maintain the momentum,” as that occurs. “What we’ll do as their partners is pick up our pace of operations, our rate of fire if you will, so they can posture themselves for the next big step.”

Townsend, who takes over command from Lt. Gen. Sean MacFarland on Sunday, said that acceleration would include intensified air and artillery strikes and also stepped-up efforts to equip and train local forces. It will not include an immediate expansion of the U.S. ground role, he said.

Iraqi and Syrian forces will require time to regroup and relocate before attempting to recapture Mosul and Raqqa, both cities that are expected to be fiercely defended, the general said. Intensified attacks by U.S. and allied planes would give those local forces “the breathing space to do that,” he said.

Townsend, a veteran of previous insurgent battles, appeared to be optimistic that despite what are expected to be extended campaigns, both cities would be ultimately fully recovered. “Our tour is a year long, and I anticipate being busy with that the bulk of the tour,” he said. “But it’s my intent to have liberated Mosul and Raqqa and be in a pursuit phase by the end of our tour.”

The general cautioned that the Islamic State would continue to pose a threat in small cities and towns, and in rural areas of both Iraq and Syria, even when that does occur. He named the city of Tal Afar, in northern Iraq to the west of Mosul, as one such place.

Townsend takes over the U.S.-led campaign as Iraqi forces are working to recapture areas surrounding Mosul in an attempt to isolate the city. With significant on-the-ground support from U.S. and allied forces, and buoyed by recent victories elsewhere, an array of Iraqi forces appear to be preparing to launch a well-resourced campaign for the city.

In Syria, the outlook is much less clear, as sustained Russian air operations and a new Syrian salvo on U.S.-backed Kurdish forces raise questions about U.S. plans there.

Last week, the United States sent fighter jets to eastern Syria when Syrian government war planes conducted unprecedented strikes on Kurdish groups around the city of Hasakah. A small number of U.S. Special Operations forces are also based around Hasakah as part of the effort to build up a local  force capable of moving on Raqqa.

Townsend said the U.S. government had discussed the incident with Russian officials, who signaled that their influence over Syrian government actions may be limited. “I’m hoping that the Syrian regime gets the word and keeps their forces away from us,” he said.

At the same time, recent moves by Kurdish fighters have raised questions about the extent to which those forces, who make up the biggest share of the U.S.-backed Syrian Democratic Forces, share America’s urgency to capture Raqqa or whether they will prioritize consolidation of Kurdish-controlled territory across Syria.

Townsend said the Kurdish forces had been “great partners” and would be a necessary component of any force that eventually launched an assault on Raqqa.

“We’re going to move out together,” he said. “Will we have differences of opinion about how to go about it, how to prosecute the campaign? Probably so … but in the end we’ll come to a common view about what we have to do next.”

Townsend, who has served as the commander of the XVIII Airborne Corps since 2015, previously commanded U.S. troops in areas of Iraq and Afghanistan rife with insurgent activity.

The general said he wasn’t sure if the next stage of Iraq and Syria operations would require additional U.S. forces. There are about 300 U.S. Special Operations troops in Syria and about 6,000 U.S. troops, including personnel on temporary duty, in Iraq.