The United States has offered to help Yemen in its "fight against terrorism" and assist the country with its reforms, the Yemeni state news agency Saba said late on Sunday.
U.S. President Barack Obama said in a letter delivered by his counterterrorism adviser John Brennan to Yemeni President Ali Abdullah Saleh that the United States will "stand beside Yemen, its unity, security and stability."
The Arab world's poorest country is battling a Shiite revolt in the north, separatist unrest in the south, and intensified al-Qaeda militancy.
International concern over Yemen has heightened because instability there could endanger neighbors including Saudi Arabia and complicate efforts to combat al-Qaeda and piracy in the Gulf of Aden.
"Yemen's security is vital to the security of the United States and the region, and America will adopt an initiative to help Yemen ... face development challenges and support reform efforts," Obama's letter said.
Obama said al-Qaeda was a "common threat...dangerous to everyone", Saba reported.
In August, a new wave of fighting erupted between rebel Shiite Muslims of the Zaydi sect and government forces trying to impose central authority. The conflict first began in 2004.
A Yemeni official told Reuters early on Monday that Brennan discussed with Saleh the importance of Yemen's continuation of economic and political reforms.
The meeting discussed Yemen's counterterrorism efforts and the assistance the U.S. might offer in this regard, without giving further details, the official said.
Yemen's security is vital to the security of the United States and the region, and America will adopt an initiative to help Yemen
U.S. President Barack Obama