U.N. Secretary-General Kofi Annan will send Jose Antiono Ocampo, undersecretary-general for economic and social affairs, to Bolivia to observe the volatile situation there, U.N. spokeswoman Marie Okabe has said. Bolivian President Carlos Mesa has offered his resignation amid weeks of massive protests and a blockade of the capital, La Paz. So far, demonstrators have prevented a meeting of Congress to select a successor to Mesa. "The secretary-general continues to follow closely the situation in Bolivia and reiterates his concern about the critical juncture the country is going through," Okabe said, adding that Annan advised Bolivians to resolve their differences peacefully and democratically. Mesa is the second president to leave office in less than five years, and the two successors to Mesa under Bolivia's constitution have been widely criticized by demonstrators. Ocampo will depart for Bolivia to observe the situation. "The timing of this mission will be determined by developments in the country," said Okabe.