TAIPEI, April 25 (Reuters) - Guatemalan President Alejandro Giammattei pledged his unconditional support on Tuesday for the "Republic of Taiwan" on a trip that comes as China steps up pressure on the handful of countries that still maintain formal ties with the island. Speaking later at Taiwan's parliament, Giammattei continued to refer to the "Republic of Taiwan", and won a standing ovation from lawmakers with a further strong message of support, ending that speech with: "Long live Taiwan: free, sovereign and independent. See here for a complete list of exchanges and delays