The United States Assistant Secretary of State for African Affairs Johnnie Carson who arrived in Nigeria on Saturday will hold bilateral talks with Vice President Goodluck Jonathan today in Abuja.

Mr Carson is also scheduled to meet today with the Secretary to the Government of the Federation Mahmud Yayale Ahmed and Foreign Affairs Minister Ojo Madueke. He has already met will civil society organizations.

The US envoy would discuss issues of governance, elections, corruption, trade improvement and investment opportunities with Nigerian officials, a statement by the US said.

Carson's visit comes at the time of political tension over the absence President Umaru Yar'adua who has been in Saudi Arabia since November 23 receiving treatment for a heart condition.

"The US government looks forward to working with the government of Nigeria as a partner on aviation security and other measures to combat international terrorism," the statement added.

There have been mounting calls from several quarters including the United States for ailing President Yar'adua to write a medical vacation letter to the National Assembly in line with the constitution.

A vacation letter from the president to the National Assembly will pave the way for Jonathan to be declared acting president.

Relationship between Nigeria and the United States was strained after Nigeria was placed on a terror watch list following an alleged failed bombing of a US plane by a Nigerian, Umar Farouk Abdulmutallab, on Christmas Day.