RIYADH/DUBAI: Fighting in Yemen has intensified as Houthi forces move to capture strategic mountain positions that could help them cut off the Red Sea coast from territory still controlled by Saudi-backed government forces.

The Iran-aligned Houthis have made a rapid advance across parts of Yemen this month, opening a new front in the wider Middle East conflict and raising further concerns about threats to global energy and shipping routes.

The developments came after a report that U.S. President Donald Trump canceled planned airstrikes against the Houthis at the last minute on September 20, despite a request for military support from Saudi Arabia.

The New York Times reported that the Trump administration had prepared to carry out airstrikes against Houthi targets following fresh appeals from Saudi Crown Prince Mohammed bin Salman.

The newspaper said Trump later ordered the strikes to be called off while U.S. troops were loading bombs onto aircraft. Reuters was unable to independently confirm the report.

On September 20, Rashid al-Alimi, president of Yemen's Saudi-backed and internationally recognized government, spoke to Trump by phone and requested U.S. military assistance, four sources told Reuters.

Two of those sources, one Yemeni and one Western, said Trump did not directly commit to providing military support during the conversation.

The Houthis have controlled Yemen's capital, Sanaa, since 2014. Their latest offensive has seen them capture parts of the country's Red Sea coast after defeating forces loyal to the Saudi-backed government.

The group is now seeking to expand its control further inland by capturing the Kahboub Mountains, a strategically important area in the provinces of Taiz and Lahij, according to five Yemeni military sources.

The mountain range is important because it lies between the Red Sea coast and government-controlled areas farther south. Control of the heights could give the Houthis a stronger position to maintain their recent territorial gains and pressure government forces.

Fighting has been reported around the remote Al-Wazi'iyah district in Taiz province and near Ras al-Ara on the Indian Ocean coast. The area lies between the Bab el-Mandeb Strait, the narrow gateway at the southern end of the Red Sea, and Aden, the main base of the internationally recognized government.

The latest fighting is part of a wider Houthi offensive that has rapidly changed the military situation in western Yemen. The group's gains have also increased concern about the security of one of the world's most important shipping routes.

The Bab el-Mandeb connects the Red Sea with the Gulf of Aden and the wider Indian Ocean. Any further Houthi expansion in the area could pose additional risks to commercial shipping and energy supplies.

Saudi Arabia has repeatedly sought greater U.S. involvement against the Houthis, but Washington has so far declined to join the Saudi-backed military campaign in Yemen.

Yemeni journalist and political analyst Mohammed Al-Qadhi said the government forces had been largely on the defensive after losing the Bab el-Mandeb area, while the Houthis were trying to maintain the pace of their advance.

"The government forces appear to remain largely in a defensive posture following the loss of the Bab el-Mandeb area, while the Houthis are seeking to maintain the momentum of their advance, despite being exposed to intensive air strikes," Al-Qadhi said.

He said the Kahboub Mountains could become an important battlefield in deciding whether the Houthis could strengthen their recent gains or whether government forces could hold enough territory to launch a counterattack.