Is the Presidency a strong or weak office?, why?

Relatively weak. A president is weak compared to a prime minister because a Prime Minister has executive and legislative power as well not being a candidate in elections. Instead, his or her party is elected and he or she is selected by the party with plurality to be prime minister. however, a prime minister can be voted out anytime with a vote of no confidence whereas a president has a set term. the president can hardly do anything really without congress, as we see now with the debt ceiling issue.